Q1) what is DevOps
By the name DevOps, it’s very clear that it’s
acollaboration of Development as well as Operations. But one should know
thatDevOps is not a tool, or a software or framework, DevOps is a
Combination ofTools which helps for the automation of whole infrastructure.
DevOps is basically and implementation of Agile methodologyon Development
side as well as Operations side.
Q2) why do we need DevOps
To fulfil the need of delivering more and faster
and betterapplication to meet more and more demands of users, we need
DevOps. DevOps helpsdeployment to happen really fast compared to any other
traditional tools.
Q3) Mention the key aspects or
principle behindDevOps
The key aspects or principle behind DevOps is :
Infrastructure as a Code Continuous Integration ContinuousDeployment
Automation Continuous Monitoring Security
Q4) Lis t out some of the popular
tools for DevOps
Git Jenkins Ansible Puppet NagiosDocker ELK
(Elasticsearch, Logstash, Kibana)
Q5) what is a version
controlsystem
Version ControlSystem (VCS) is a software that
helpssoftware developers to work together and maintain a complete his tory
of theirwork. Some of the feature of VCS as follows: Allow developers towok
simultaneously Does not allow overwriting on each other changes. Maintainthe
his tory of every version. There are two types of Version ControlSystems:
Central Version ControlSystem, Ex: Git, Bitbucket Dis tributed/Decentralized
Version ControlSystem, Ex:SVN
Q6) What is Git and explain the
difference between Git andSVN
Git is a source code management (SCM) toolwhich
handlessmall as well as large projects with efficiency. It is basically used
to storeour repositories in remote server such as GitHub. GIT SVN Git is a
Decentralized Version ControlTool SVN is a Centralized Version ControlTool
Git contains the local repo as well asthe full his tory of the whole project
on all the developershard drive, so if there is a server outage , you can
easilydo recovery from your team mates local git repo. SVN relies only on
the central server tostore all the versions of the project file Push and
pull operations are fast Push and pull operations are slowercompared to Git
It belongs to 3 rd generation Version ControlTool It belongs to 2 nd
generation Version Controltools Client nodes can share the
entirerepositories on their local system Version his tory is stored on
server-siderepository Commits can be done offline too Commits can be done
only online Work are shared automatically bycommit Nothing is shared
automatically
Q7) what language is used in Git
Git is written in C language, and since its written
in Clanguage its very fast and reduces the overhead of runtimes.
Q8) what is SubGit
SubGit is a toolfor migrating SVN to Git. It
creates awritable Git mirror of a local or remote Subversion repository and
uses bothSubversion and Git if you like.
Q9) how can you clone a Git
repository via Jenkins
First, we must enter the e-mail and user name for
yourJenkins system, then switch into your job directory and execute the
“gitconfig” command.
Q10)What are the Advantages of
Ansible
Agentless, it doesn’t require any
extrapackage/daemons to be installed Very low overhead Good performance
Idempotent Very Easy to learn Declarative not procedural
Q11) what’s the use of Ansible
Ansible is mainly used in IT infrastructure to
manage ordeploy applications to remote nodes. Let’s say we want to deploy
oneapplication in 100’s of nodes by just executing one command, then
Ansibleis the one actually coming into the picture but should have some
knowledge onAnsible script to understand or execute the same.
Q12) what’s the difference
between Ansible Playbookand Roles
Roles Playbooks Roles are reusable subsets of
aplay. Playbooks contain Plays. A set of tasks for accomplis hing
certainrole. Mapps among hosts and roles. Example: common, webservers.
Example: site.yml, fooservers.yml,webservers.yml.
Q13) How do I see a lis t of all
the ansible_variables
Ansible by default gathers “facts” about
themachines, and these facts can be accessed in Playbooks and in templates.
To seea lis t of all the facts that are available about a machine, you can
run the“setup” module as an ad-hoc action: Ansible -m setup hostname This
will print out a dictionary of all the facts that areavailable for that
particular host.
Q14) what is Docker
Docker is a containerization technology that
packages yourapplication and all its dependencies together in the form of
Containers toensure that your application works seamlessly in any
environment.
Q15) what is Docker image
Docker image is the source of Docker container. Or
in otherwords, Docker images are used to create containers.
Q16) what is Docker Container
Docker Container is the running instance of
DockerImage.
Q17) Can we consider DevOps as
Agile methodology
Of Course, we can!! The only difference between
agilemethodology and DevOps is that, agile methodology is implemented only
fordevelopment section and DevOps implements agility on both development as
well asoperations section.
Q18) what are the advantages of
using Git
Data redundancy and replication High availability
Only one. git directory per repository Superior dis k utilization and
network performanceCollaboration friendly Git can use any sort of projects.
Q19) what is kernel
A kernel is the lowest level of easily replaceable
softwarethat interfaces with the hardware in your computer.
Q20) what is difference between
grep -i and grep -v
I ignore alphabet difference V accept this value
ex) ls |grep -i docker Dockerfile docker.tar.gz ls | grep -v docker Desktop
Dockerfile DocumentsDownloads You can’t see anything with name docker.tar.gz
Q21) How can you define particular space to the file This feature is
generally used to give the swap space to theserver. Lets say in below
machine I have to create swap space of 1GBthen, dd if=/dev/zero
of=/swapfile1 bs=1G count=1
Q22) what is concept of sudo in
linux
Sudo(superuser do) is a utility for UNIX- and
Linux-basedsystems that provides an efficient way to give specific users
permis sion to usespecific system commands at the root (most powerful) level
of the system.
Q23) what is a Jenkins Pipeline
Jenkins Pipeline (or simply “Pipeline”) is asuite
of plugins which supports implementing and integrating continuous
deliverypipelines into Jenkins.
Q24) How to stop and restart the
Docker container
To stop the container: docker stop container ID Now
to restart the Docker container: docker restartcontainer ID
Q25) What platforms does Docker
run on
Docker runs on only Linux and Cloud platforms:
Ubuntu 12.04 LTS+ Fedora 20+ RHEL 6.5+ CentOS 6+ Gentoo ArchLinux openSUSE
12.3+ CRUX 3.0+ Cloud: Amazon EC2 Google Compute Engine Microsoft Azure
Rackspace Note that Docker does not run on Windows or Mac forproduction as
there is no support, yes you can use it for testing purpose evenin windows
Q26) what are the tools used for
docker networking
For docker networking we generally use kubernets
and dockerswarm.
Q27) what is docker compose
Lets say you want to run multiple docker container,
at thattime you have to create the docker compose file and type the
commanddocker-compose up. It will run all the containers mentioned in docker
composefile.
Q28) What is Scrum
Scrum is basically used to divide your complex
software andproduct development task into smaller chunks, using iterations
and incrementalpractis es. Each iteration is of two weeks. Scrum consis ts
of three roles:Product owner, scrum master and Team
Q29) What does the commit object
contain
Commit object contain the following components: It
contains a set of files, representing the state of aproject at a given point
of time reference to parent commit objects An SHAI name, a 40-character
string that uniquely identifiesthe commit object (also called as hash).
Q30) Explain the difference
between git pull and gitfetch
Git pull command basically pulls any new changes or
commitsfrom a branch from your central repository and updates your target
branch inyour local repository. Git fetch is also used for the same purpose,
but itsslightly different form Git pull. When you trigger a git fetch, it
pulls all newcommits from the desired branch and stores it in a new branch
in your localrepository. If we want to reflect these changes in your target
branch, git fetchmust be followed with a git merge. Our target branch will
only be updated aftermerging the target branch and fetched branch. Just to
make it easy for us,remember the equation below: Git pull = git fetch + git
merge
Q31) How do we know in Git if a
branch has already beenmerged into master
git branch –merged The above command lis ts the
branches that have been mergedinto the current branch. git branch –no-merged
this command lis ts the branches that have not beenmerged.
Q32) What is ‘Staging Area’
or‘Index’ in GIT
Before committing a file, it must be formatted and
reviewedin an intermediate area known as ‘Staging Area’ or ‘IndexingArea’.
#git add
Q33) What is Git Stash
Let’s say you’ve been working on part of
yourproject, things are in a messy state and you want to switch branches for
sometime to work on something else. The problem is , you don’t want to do
acommit of your half-done work just, so you can get back to this point
later. Theanswer to this is sue is Git stash. Git Stashing takes your
working directory that is , yourmodified tracked files and staged changes
and saves it on a stack of unfinis hedchanges that you can reapply at any
time.
Q34) What is Git stash drop
Git ‘stash drop’ command is basically used toremove
the stashed item. It will basically remove the last added stash item
bydefault, and it can also remove a specific item if you include it as
anargument. I have provided an example below: If you want to remove any
particular stash item from thelis t of stashed items you can use the below
commands: git stash lis t: It will dis play the lis t of stashed items
asfollows: stash@{0}: WIP on master: 049d080 added the index filestash@{1}:
WIP on master: c265351 Revert “added files” stash@{2}:WIP on master: 13d80a5
added number to log
Q35) What is the function of
‘gitconfig’
Git uses our username to associate commits with an
identity.The git config command can be used to change our Git configuration,
includingyour username. Suppose you want to give a username and email id
toassociate commit with an identity so that you can know who has made a
commit.For that I will use: git config –global user.name “Your Name”:This
command will add your username. git config –global user.email “Your
E-mailAddress”: This command will add your email id.
Q36) How can you create a
repository in Git
To create a repository, you must create a directory
for theproject if it does not exis t, then run command “git init”. Byrunning
this command .git directory will be created inside the projectdirectory.
Q37) Describe the branching
strategies you haveused
Generally, they ask this question to understand
yourbranching knowledge Feature branching This model keeps all the changes
for a feature inside of abranch. When the feature branch is fully tested and
validated by automatedtests, the branch is then merged into master. Task
branching In this task branching model each task is implemented on itsown
branch with the task key included in the branch name. It is quite easy tosee
which code implements which task, just look for the task key in the
branchname. Release branching Once the develop branch has acquired enough
features for arelease, then we can clone that branch to form a Release
branch. Creating this release branch starts the next release cycle, so no
new features can be addedafter this point, only bug fixes, documentation
generation, and otherrelease-oriented tasks should go in this branch. Once
it’s ready to ship,the release gets merged into master and then tagged with
a version number. Inaddition, it should be merged back into develop branch,
which may haveprogressed since the release was initiated earlier.
Q38) What is Jenkins
Jenkins is an open source continuous integration
toolwhichis written in Java language. It keeps a track on version
controlsystem and toinitiate and monitor a build system if any changes
occur. It monitors the wholeprocess and provides reports and notifications
to alert the concern team.
Q39) What is the difference
between Maven, Ant andJenkins
Maven and Ant are Build Technologies whereas
Jenkins is acontinuous integration(CI/CD) tool.
Q40) Explain what is continuous
integration
When multiple developers or teams are working on
differentsegments of same web application, we need to perform integration
test byintegrating all the modules. To do that an automated process for each
piece ofcode is performed on daily bases so that all your code gets tested.
And this whole process is termed as continuous integration.
Q41) What is the relation between
Hudson andJenkins
Hudson was the earlier name of current Jenkins.
After someis sue faced, the project name was changed from Hudson to Jenkins.
Q42) What are the advantages of
Jenkins
Advantage of using Jenkins Bug tracking is easy at
early stage in developmentenvironment. Provides a very large numbers of
plugin support. Iterative improvement to the code, code is basically
dividedinto small sprints. Build failures are cached at integration stage.
For each code commit changes an automatic build reportnotification get
generated. To notify developers about build report success or failure,it can
be integrated with LDAP mail server. Achieves continuous integrationagile
development and test-driven development environment. With simple steps,
maven release project can also beautomated.
Q43) Which SCM tools does Jenkins
supports
Source code management tools supported by Jenkins
arebelow: AccuRev CVS Subversion Git Mercurial Perforce Clearcase RTC
Q44) What is Ansible
Ansible is a software configuration management
tooltodeploy an application using ssh without any downtime. It is also used
formanagement and configuration of software applications. Ansible is
developed inPython language.
Q45) How can your setup Jenkins
jobs
Steps to set up Jenkins job as follows: Select new
item from the menu. After that enter a name for the job (it can be anything)
andselect free-style job. Then click OK to create new job in
Jenkinsdashboard. The next page enables you to configure your job, andit’s
done.
Q46) What is your daily
activities in your currentrole
Working on JIRA Tickets Builds and Deployments
Resolving is sues when builds and deployments fails bycoordinating and
collaborating with the dev team Infrastructuremaintenance Monitoring health
of applications
Q47) What are the challenges you
faced in recenttimes
I need to implement trending technologies like
Docker toautomate the configuration management activities in my project by
showingPOC.
Q48) What are the build and
deployment failures you got andhow you resolved those
I use to get most of the time out of memory is sue.
So Ifixed this is sue by restarting the server which is not best practice. I
did thepermanent fix by increase the Perm Gen Space and Heap Space.
Q49) I want a file that consis ts
of last 10 lines of thesome other file
Tail -10 filename >filename
Q50) How to check the exit status
of the commands
echo $
Q51) I want to get the information from file which
consis tsof the word “GangBoard” grep “GangBoard” filename Q52) I want to
search the files with the name of“GangBoard” find / -type f -name
“*GangBoard*”
Q53) Write a shell script to
print only primenumbers
prime.sh echo "1" i=3j=300 flag=0 tem=2 echo
"1"while [ $i -ne $j ] do temp=`echo $i` while [ $temp -ne $tem ] do
temp=`expr $temp - 1` n=`expr $i % $temp` if [ $n -eq 0 -a $flag -eq 0 ]
then flag=1 fi done if [ $flag -eq 0 ] then else fi echo $i flag=0 i=`expr
$i + 1` done
Q54) How to pass the parameters
to the script and how can Iget those parameters
Scriptname.sh parameter1 parameter2 I will use $*
to get theparameters.
Q55) What is the default file
permis sions for the file andhow can I modify it
Default file permis sions are : rw-r—r— If I want
to change the default file permis sions I need touse umask command ex: umask
666
Q56) How you will do the releases
There are some steps to follow. Create a check lis
t Create a release branch Bump the version Merge release branch to master &
tag it. Use a Pull request to merge the release merge Deploy masterto Prod
Environment Merge back into develop & delete release branch Changelog
generation Communicating with stack holders Grooming the is suetracker
Q57) How you automate the whole
build and releaseprocess
Check out a set of source code files. Compile the
code and report on progress along the way. Runautomated unit tests against
successful compiles. Create an installer. Publis h the installer to a
download site, and notify teamsthat the installer is available. Run the
installer to create an installedexecutable. Run automated tests against the
executable. Report theresults of the tests. Launch a subordinate project to
update standard libraries.Promote executables and other files to QA for
further testing. Deploy finis hed releases to production environments, such
asWeb servers or CD manufacturing. The above process will be done by Jenkins
by creating thejobs. Q58) I have 50 jobs in the Jenkins dash board , I want
tobuild at a time all the jobs In Jenkins there is a plugin called build
after otherprojects build. We can provide job names over there and If one
parent job runthen it will automatically run the all other jobs. Or we can
use Pipe linejobs.
Q59) How can I integrate all the
tools with Jenkins
I have to navigate to the manage Jenkins and then
globaltoolconfigurations there you have to provide all the details such as
Git URL ,Java version, Maven version , Path etc.
Q60) How to install Jenkins via
Docker
The steps are: Open up a terminal window. Download
the jenkinsci/blueocean image & run it as acontainer in Docker using the
following docker run
command:(https://docs.docker.com/engine/reference/commandline/run/) docker
run \ -u root \ –rm \ -d \ -p 8080:8080 \ -p50000:50000 \ -v
jenkins-data:/var/jenkins_home \ -v
/var/run/docker.sock:/var/run/docker.sock \jenkinsci/blueocean Proceed to
the Post-installation setup
wizard(https://jenkins.io/doc/book/installing/#setup-wizard) Accessing
theJenkins/Blue Ocean Docker container docker exec -it jenkins-blueoceanbash
Accessing the Jenkins console log through Docker logsdockerlogs
Accessing the Jenkins home directorydockerexec -it
bash
Q61) Did you ever participated in
Prod DeploymentsIf yeswhat is the procedure
Yes I have participated, we need to follow the
followingsteps in my point of view Preparation & Planning : What kind of
system/technologywas supposed to run on what kind of machine The
specifications regarding theclustering of systems How all these stand-alone
boxes were going to talk to eachother in a foolproof manner Production setup
should be documented to bits. It needs tobe neat, foolproof, and
understandable. It should have all a system configurations, IP
addresses,system specifications, & installation instructions. It needs to be
updatedas & when any change is made to the production environment of
thesystem
Q62) My application is not coming
up for some reasonHowcan you bring it up
We need to follow the steps Network connection The
Web Server is not receiving users’s requestChecking the logs Checking the
process id’s whether services are runningor not The Application Server is
not receiving user’srequest(Check the Application Server Logs and Processes)
A network level‘connection reset’ is happening somewhere.
Q63) Did you automate anything in
your projectPleaseexplain
Yes I have automated couple of things such as
Passwordexpiry automation Deleting the older log files Code quality
threshold violations etc.
Q64) What is IaCHow you will
achieve this
Infrastructure as Code (IaC) is the management
ofinfrastructure (networks, virtual machines, load balancers, and
connectiontopology) in a descriptive model, using the same versioning as
DevOps team usesfor source code. This will be achieved by using the tools
such as Chef, Puppetand Ansible etc.
Q65) What is multifactor
authenticationWhat is the use ofit
Multifactor authentication (MFA) is a security
system thatrequires more than one method of authentication from independent
categories ofcredentials to verify the user’s identity for a login or
othertransaction. Security for every enterpris e user — end &privileged
users, internal and external Protect across enterpris e resources — cloud
&on-prem apps, VPNs, endpoints, servers, privilege elevation and more Reduce
cost & complexity with an integrated identityplatform
Q66) I want to copy the artifacts
from one location toanother location in cloud. How
Create two S3 buckets, one to use as the source,
and theother to use as the destination and then create policies.
Q67) How can I modify the commit
message in git
I have to use following command and enter the
requiredmessage. Git commit –amend Q68) How can you avoid the waiting time
for the triggeredjobs in Jenkins. First I will check the Slave nodes
capacity, If it is fullyloaded then I will add the slave node by doing the
following process. Go to the Jenkins dashboard -> Manage Jenkins
->ManageNodes Create the new node a By giving the all required fields and
launch the slavemachine as you want.
Q69) What are the Pros and Cons
of Ansible
Pros: Open Source Agent less Improved efficiency ,
reduce cost Less Maintenance Easy to understand yaml files Cons:
Underdeveloped GUI with limited features Increased focus on orchestration
over configurationmanagement SSH communication slows down in scaled
environments
Q70) How you handle the merge
conflicts in git
Follow the steps Create Pull request Modify
according to the requirement by sitting withdevelopers Commit the correct
file to the branch Merge the current branch with master branch.
Q71) I want to delete 10 days
older log files. How canI
There is a command in unix to achieve this task
find -mtime +10 -name “*.log” -exec rm -f {} \; 2>/dev/null
What is the difference among
chef, puppet andansible
Chef Puppet Ansible Interoperability Works Only on
Linux/Unix Works Only on Linux/Unix Supports Windows but server should
beLinux/U Conf. Language It uses Ruby Puppet DSL YAML (Python) Availability
Primary Server and Backup Server Multi Master Architecture Single Active
Node
Q72) How you get the Inventory
variables defined for thehost
We need to use the following command Ansible – m
debug- a“var=hostvars[‘hostname’]”localhost(10.92.62.215)
Q73) How you will take backup for
Jenkins
Copy JENKINS_HOME directory and “jobs” directoryto
replicate it in another server
Q74) How to deploy docker
container to aws
Amazon provides the service called Amazon Elastic
ContainerService; By using this creating and configuring the task definition
and serviceswe will launch the applications.
Q75) I want to change the default
port number of apachetomcat. How
Go to the tomcat folder and navigate to the conf
folderthere you will find a server.xml file. You can change connector port
tag as youwant.
Q76) In how many ways you can
install the Jenkins
We can install Jenkins in 3 Ways By downloading
Jenkinsarchive file By running as a service Java –jar Jenkins.war By
deploying Jenkins.war to the webapps folder intomcat.
Q77) How you will run Jenkins job
from command line
We have a Jenkins CLI from there we need to use the
curlcommand curl -X POST -u YOUR_USER:YOUR_USER_PASSWORD
http://YOUR_JENKINS_URL/job/YOUR_JOB/build
Q78) How you will do tagging in
git
We have following command to create tags in git Git
tagv0.1
Q79) How can you connect a
container to a network when itstarts
We need to use a following command docker run -itd
–network=multi-host-networkbusybox
Q80) How you will do code commit
and code deploy incloud
Create a deployment environment Get a copy of the
samplecode Create your pipeline Activate your pipeline Commit a change and
update the App.
Q81) How to access variable names
in Ansible
Using hostvars method we can access and add the
variableslike below {{ hostvars[inventory_hostname][‘ansible_’ +
which_interface][‘ipv4’][‘address’] }}
Q82) What is Infrastructure as
Code
Where the Configuration of any servers or toolchain
orapplication stack required for an association can be made into
progressivelyelucidating dimension of code and that can be utilized for
provis ioning andoverseeing foundation components like Virtual Machine,
Software, NetworkElements, however it varies from contents utilizing any
language, where they area progression of static advances coded, where
Version controlcan be utilized soas to follow condition changes . Precedent
Tools are Ansible, Terraform.
Q83) What are the zones the
Version controlcan acquaintwith get proficient DevOps practice
A clearly fundamental region of Version Controlis
Sourcecode the executives, Where each engineer code ought to be pushed to a
typicalstorehouse for keeping up assemble and dis charge in CI/CD pipelines.
Another territory can be Version controlFor Adminis tratorswhen they use
Infrastructure as A Code (IAC) apparatuses and rehearses forkeeping up The
Environment setup. Another Area of Version Controlframework Can be
ArtifactoryManagement Using Repositories like Nexus and DockerHub
Q84) Why Opensource apparatuses
support DevOps
Opensource devices dominatingly utilized by any
associationwhich is adjusting (or) embraced DevOps pipelines in light of the
fact thatdevops accompanied an attention on robotization in different parts
ofassociation manufacture and dis charge and change the executives and
furthermoreframework the board zones. So creating or utilizing a solitary
apparatus is unthinkableand furthermore everything is fundamentally an
experimentation period ofadvancement and furthermore coordinated chops down
the advantage of building upa solitary device , so opensource devices were
accessible available practicallyspares each reason and furthermore gives
association a choice to assess thedevice dependent on their need.
Q85) What is the dis tinction
among Ansible and chef(or)manikin
Ansible is Agentless design the board device, where
manikinor gourmet expert needs operator should be kept running on the
specialis t huband culinary specialis t or manikin depends on draw
demonstrate, where yourcookbook or show for gourmet expert and manikin
separately from the ace will bepulled by the operator and ansible uses ssh
to convey and it gives informationdriven guidelines to the hubs should be
overseen , progressively like RPCexecution, ansible utilizations YAML
scripting, though manikin (or) culinaryspecialis t is worked by ruby uses
their own DSL .
Q86) What is Jinja2 templating in
ansible playbooks andtheir utilization
Jinja2 templating is the Python standard for
templating ,consider it like a sed editorial manager for Ansible , where it
very well may beutilized is when there is a requirement for dynamic change
of any config recordto any application like consider mapping a MySQL
application to the IP addressof the machine, where it is running, it can’t
be static , it needsmodifying it progressively at runtime. Arrangement The
vars inside the supports are supplanted by ansible whilerunning utilizing
layout module.
Q87) What is the requirement for
sorting out playbooks asthe job, is it vital
Arranging playbooks as jobs , gives greater clarity
andreusability to any plays , while consider an errand where MySQL establis
hmentought to be done after the evacuation of Oracle DB , and another
prerequis ite is expected to introduce MySQL after java establis hment, in
the two cases we haveto introduce MySQL , yet without jobs need to compose
playbooks independentlyfor both use cases , yet utilizing jobs once the
MySQL establis hment job is madecan be used any number of times by summoning
utilizing rationale in site.yaml. No, it is n’t important to make jobs for
eachsituation, however making jobs is the best practice in Ansible.
Q88) What is the fundamental dis
service of Dockerholders
As the lifetime of any compartments is while
pursuing aholder is wrecked you can’t recover any information inside a
compartment,the information inside a compartment is lost perpetually,
however tenaciouscapacity for information inside compartments should be
possible utilizingvolumes mount to an outer source like host machine and any
NFS drivers.
Q89) What are the docker motor
and docker form
Docker motor contacts the docker daemon inside the
machineand makes the runtime condition and procedure for any compartment,
docker makeconnects a few holders to shape as a stack utilized in making
application stackslike LAMP, WAMP, XAMP
Q90) What are the Different modes
does a holder can berun
Docker holder can be kept running in two modes
Connected: Where it will be kept running in the forefront ofthe framework
you are running, gives a terminal inside to compartment when– t choice is
utilized with it, where each log will be diverted to stdoutscreen. is
olates: This mode is typically kept running underway,where the holder is
confined as a foundation procedure and each yield inside acompartment will
be diverted log recordsinside/var/lib/docker/logs/ /
andwhich can be seen by docker logs order.
Q91) What the yield of docker
assess order will be
Docker examines will give yield in
JSONposition, which contains subtleties like the IP address of the
compartmentinside the docker virtual scaffold and volume mount data and
each other dataidentified with host (or) holder explicit like the basic
document driverutilized, log driver utilized. docker investigate
[OPTIONS] NAME|ID [NAME|ID…]Choices Name, shorthand Default Description
group, – f Format the yield utilizing the given Golayout measure, – s
Dis play all out document sizes if thesort is the compartment type
Return JSON for a predefined type
Q92) What is the order can be
utilized to check the assetusage by docker holders
Docker details order can be utilized to check the
assetusage of any docker holder, it gives the yield practically equivalent
to Topdirection in Linux, it shapes the base for compartment asset
observinginstruments like a counsel, which gets yield from docker details
order. docker details [OPTIONS] [CONTAINER…] Choices Name, shorthand Default
Description all, – a Show all holders (default demonstrates simplyrunning)
group Pretty-print pictures utilizing a Go layout no-stream Dis able
spilling details and just draw the mainoutcome no-trunc Do not truncate
yield
Q93) How to execute some errand
(or) play on localhost justwhile executing playbooks on various has on
an ansible
In ansible, there is a module called delegate_to,
in this module area give the specific host (or) has where your errands (or)
assignmentshould be run. undertakings: name: ” Elasticsearch Hitting”
uri:
url=’_searchq=status:new’headers='{“Content-type”:”application/json”}’method=GET
return_content=yes
regis ter: yield delegate_to: 127.0.0.1
Q94) What is the dis tinction
among set_fact and vars inansible
Where a set_fact sets the incentive for a factor at
one timeand stays static, despite the fact that the esteem is very powerful
and varscontinue changing according to the esteem continues changing for
thevariable. assignments: set_fact: fact_time: “Truth: ” troubleshoot:
var=fact_timeorder: rest 2 troubleshoot: var=fact_time assignments: name:
queries in factors versus queries in realities has:localhost vars: var_time:
“Var: ” Despite the fact that the query for the date has beenutilized in
both the cases, wherein the vars are utilized it modifies dependenton an
opportunity to time each time executed inside the playbook lifetime. Bethat
as it may, Fact dependably continues as before once query is finis hed
Q95) What is a query in ansible
and what are query modulesbolstered by ansible
Query modules enable access to information in
Ansible fromoutside sources. These modules are assessed on the Ansible
controlmachine andcan incorporate perusing the filesystem yet in addition
reaching outsideinformation stores and adminis trations. Organization is
{lookup{‘
’,' ’}}A portion of the
query modules upheld by ansible are Document pipe redis jinja
layouts etcd kv store
Q96) How might you erase the
docker pictures put away atyour nearby machine and how might you do it
for every one of the pictureswithout a moment’s delay
The direction docker RMI can be utilized
toerase the docker picture from nearby machine, though a few pictures
may shouldbe constrained in light of the fact that the picture might be
utilized by someother holder (or) another picture , to erase pictures
you can utilize the mix ofdirections by docker RMI $(docker pictures –
q), where docker pictures willgive the docker picture names, to get just
the ID of docker pictures just , weare utilizing – q switch with docker
pictures order.
Q97) What are the organizers in
the Jenkins establis hmentand their employments
JENKINS_HOME – which will be/$JENKINS_USER/.jenkins
itis the root envelope of any Jenkins establis hment and it contains
subfolderseach for various purposes. employments/ – Folder contains all the
data prettymuch every one of the occupations arranged in the Jenkins
example. Inside employments/, you will have the envelope made foreach
activity and inside those organizers, you will have fabricate organizers
asindicated by each form numbers each form will have its log records, which
we seein Jenkins web support. Modules/ – where all your modules will
berecorded. Workspace/ – this will be available to hold all theworkspace
documents like your source code pulled from SCM.
Q98) What are the approaches to
design Jenkinsframework
Jenkins can be designed in two different ways Web:
Where there is a choice called design a framework, intheir area, you can
make all setup changes. Manual on filesystem: Where each change should
likewis e bepossible straightforwardly on the Jenkins config.xml document
under the Jenkinsestablis hment catalog, after you make changes on the
filesystem, you have torestart your Jenkins, either can do it specifically
from terminal (or) you canutilize Reload setup from plate under oversee
Jenkins menu or you canhit/restart endpoint straightforwardly.
Q99) What is the job Of HTTP REST
API in DevOps
As DevOps is absolutely centers around Automating
yourframework and gives changes over the pipeline to various stages like an
everyCI/CD pipeline will have stages like form, test, mental soundness test,
UAT,Deployment to Prod condition similarly as with each phase there are
diversedevices is utilized and dis tinctive innovation stack is dis played
and thereshould be an approach to incorporate with various instrument for
finis hing anarrangement toolchain, there comes a requirement for HTTP API ,
where eachapparatus speaks with various devices utilizing API , and even
client canlikewis e utilize SDK to interface with various devices like BOTOX
for Python tocontact AWS API’s for robotization dependent on occasions ,
these days itsnot cluster handling any longer , it is generally occasion
drivenpipelines
Q100) What are Micro services,
and how they controlproficient DevOps rehearses
Where In conventional engineering , each
application is stone monument application implies that anything is created
by a gathering ofdesigners, where it has been sent as a solitary application
in numerous machinesand presented to external world utilizing load balances,
where the microservices implies separating your application into little
pieces, where eachpiece serves the dis tinctive capacities expected to finis
h a solitary exchangeand by separating , designers can likewis e be shaped
to gatherings and each bitof utilization may pursue diverse rules for
proficient advancement stage, as aresult of spry improvement ought to be
staged up a bit and each adminis trationutilizes REST API (or) Message lines
to convey between anotheradminis tration. So manufacture and arrival of a
non-strong form may notinfluence entire design, rather, some usefulness is
lost, that gives theconfirmation to productive and quicker CI/CD pipelines
and DevOpsPractices.
Q101) What are the manners in
which that a pipeline can bemade in Jenkins
There are two different ways of a pipeline can be
made inJenkins Scripted Pipelines: Progressively like a programming approach
Explanatory pipelines: DSL approach explicitly to make Jenkins pipelines.
The pipeline ought to be made in Jenkins document and thearea can either be
in SCM or nearby framework. Definitive and Scripted Pipelines are developed
on a verybasic level in an unexpected way. Definitive Pipeline is a later
element ofJenkins Pipeline which: gives more extravagant grammatical
highlights over ScriptedPipeline language structure, and is intended to make
composing and perusingPipeline code less demanding.
Q102) What are the Labels in
Jenkins and where it tends tobe used
Similarly as with CI/CD arrangement should be
concentrated ,where each application in the association can be worked by a
solitary CI/CDserver , so in association there might be various types of
utilization likejava, c#,.NET and so forth, likewis e with microservices
approach yourprogramming stack is inexactly coupled for the task , so you
can have Labeled inevery hub and select the choice Only assembled
employments while namecoordinating this hub, so when a manufacture is
planned with the mark of the hubpresent in it, it hangs tight for next agent
in that hub to be accessible,despite the fact that there are different
agents in hubs.
Q103) What is the utilization of
Blueocean inJenkins
Blue Ocean reconsiders the client experience of
Jenkins.Planned from the beginning for Jenkins Pipeline, yet at the same
time good withfree-form occupations, Blue Ocean diminis hes mess and builds
lucidity for eachindividual from the group. It gives complex UI to recognize
each phase of the pipelineand better pinpointing for is sues and extremely
rich Pipeline editorial managerfor apprentices.
Q104) What is the callback
modules in Ansible, give a fewinstances of some callback modules
Callback modules empower adding new practices to
Ansiblewhen reacting to occasions. Of course, callback modules controla
large portionof the yield you see when running the direction line programs,
however canlikewis e be utilized to include an extra yield, coordinate with
differentapparatuses and marshall the occasions to a capacity backend. So at
whateverpoint a play is executed and after it creates a few occasions, that
occasionsare imprinted onto Stdout screen, so callback module can be put
into anycapacity backend for log preparing. Model callback modules are
ansible-logstash, where eachplaybook execution is brought by logstash in the
JSON group and can beincorporated some other backend source like
elasticsearch.
Q105) What are the scripting
dialects can be utilized inDevOps
As with scripting dialects, the fundamental shell
scriptingis utilized to construct ventures in Jenkins pipelines and python
contents canbe utilized with some other devices like Ansible , terraform as
a wrappercontent for some other complex choice unraveling undertakings in
anymechanization as python is more unrivaled in complex rationale deduction
thanshell contents and ruby contents can likewis e be utilized as fabricate
venturesin Jenkins.
Q106) What is Continuous
Monitoring and why checking is basic in DevOps
DevOps draws out each association capacity of
fabricate anddis charge cycle to be a lot shorter with an idea of CI/CD,
where each change is reflected into generation conditions fastly, so it
should be firmly observed toget client input. So the idea of constant
checking has been utilized to assessevery application execution
progressively (at any rate Near Real Time) , whereevery application is
produced with application execution screen specialis tsperfect and the
granular dimension of measurements are taken out like JVMdetails and even
practical savvy measurements inside the application canlikewis e be spilled
out progressively to Agents , which thusly provides for anybackend
stockpiling and that can be utilized by observing groups in dashboardsand
cautions to get persis tently screen the application.
Q107) Give a few instances of
persis tent observinginstruments
Where numerous persis tent observing instruments
areaccessible in the market, where utilized for an alternate sort of use
andsending model Docker compartments can be checked by consultant
operator,which can be utilized by Elasticsearch to store measurements (or)
you canutilize TICK stack (Telegraph, influxdb, Chronograph, Capacitor) for
eachframework observing in NRT(Near Real Time) and You can utilize Logstash
(or)Beats to gather Logs from framework , which thusly can utilize
Elasticsearch asStorage Backend can utilize Kibana (or) Grafana as vis
ualizer. The framework observing should be possible by Nagios andIcinga.
Q108) What is docker swarm
Gathering of Virtual machines with Docker Engine
can begrouped and kept up as a solitary framework and the assets likewis e
being sharedby the compartments and docker swarm ace calendars the docker
holder in any ofthe machines under the bunch as indicated by asset
accessibility Docker swarm init can be utilized to start docker swarmbunch
and docker swarm joins with the ace IP from customer joins the hub intothe
swarm group.
Q109) What are Microservices, and
how they controlproductive DevOps rehearses
Where In conventional engineering , each
application is stone monument application implies that anything is created
by a gathering ofdesigners, where it has been conveyed as a solitary
application in numerousmachines and presented to external world utilizing
load balancers, where themicroservices implies separating your application
into little pieces, where eachpiece serves the diverse capacities expected
to finis h a solitary exchange andby separating , engineers can likewis e be
shaped to gatherings and each bit ofutilization may pursue dis tinctive
rules for proficient advancement stage, onaccount of light-footed
improvement ought to be staged up a bit and eachadminis tration utilizes
REST API (or) Message lines to impart between anotheradminis tration. So
manufacture and arrival of a non-hearty variant may notinfluence entire
design, rather, some usefulness is lost, that gives theaffirmation to
proficient and quicker CI/CD pipelines and DevOpsPractices.
Q110) What are the manners in
which that a pipeline can bemade in Jenkins
There are two different ways of a pipeline can be
made inJenkins Scripted Pipelines: Progressively like a programming approach
Explanatorypipelines: DSL approach explicitly to make Jenkins pipelines. The
pipeline ought to be made in Jenkins record and the areacan either be in SCM
or neighborhood framework. Definitive and Scripted Pipelines are developed
in a generalsense in an unexpected way. Explanatory Pipeline is a later
element of JenkinsPipeline which: gives more extravagant linguis tic
highlights over ScriptedPipeline sentence structure, and is intended to make
composing and perusingPipeline code simpler.
Q111) What are the Labels in
Jenkins and where it very wellmay be used
Likewis e with CI/CD arrangement should be
incorporated ,where each application in the association can be worked by a
solitary CI/CDserver , so in association there might be various types of use
like java,c#,.NET and so forth, similarly as with microservices approach
your programmingstack is inexactly coupled for the undertaking , so you can
have Labeled inevery hub and select the alternative Only assembled
occupations while markcoordinating this hub, so when a fabricate is booked
with the name of the hubpresent in it, it sits tight for next agent in that
hub to be accessible,despite the fact that there are different agents in
hubs.
Q112) What is the utilization of
Blueocean inJenkins
Blue Ocean reexamines the client experience of
Jenkins.Planned starting from the earliest stage for Jenkins Pipeline, yet
at the sametime good with free-form occupations, Blue Ocean lessens mess and
expandsclearness for each individual from the group. It gives modern UI to
recognize each phase of the pipelineand better pinpointing for is sues and
rich Pipeline proofreader forfledglings.
Q113) What is the callback
modules in ansible, give a fewinstances of some callback modules
Callback modules empower adding new practices to
Ansiblewhen reacting to occasions. As a matter of course, callback modules
controlthegreater part of the yield you see when running the direction line
programs, yetcan likewis e be utilized to include an extra yield, coordinate
with differentinstruments and marshall the occasions to a capacity backend.
So at whateverpoint a play is executed and after it delivers a few
occasions, that occasionsare imprinted onto Stdout screen, so callback
module can be put into anycapacity backend for log handling. Precedent
callback modules are ansible-logstash, where eachplaybook execution is
gotten by logstash in the JSON position and can beincorporated some other
backend source like elasticsearch.
Q114) What are the scripting
dialects can be utilized inDevOps
As with scripting dialects, the fundamental shell
scriptingis utilized to assemble ventures in Jenkins pipelines and python
contents can beutilized with some other instruments like Ansible.
Q115) For what reason is each
instrument in DevOps is generally has some DSL (Domain Specific
Language)
Devops is a culture created to address the
necessities oflithe procedure, where the advancement rate is quicker ,so
sending shouldcoordinate its speed and that needs activities group to
arrange and work withdev group, where everything can computerize utilizing
content based , however itfeels more like tasks group than , it gives
chaotic association of anypipelines, more the utilization cases , more the
contents should be composed ,so there are a few use cases, which will be
sufficient to cover the requirementsof light-footed are taken and
apparatuses are made by that and customization canoccur over the device
utilizing DSL to mechanize the DevOps practice and Infrathe board.
Q116) What are the mis ts can be
incorporated with Jenkinsand what are the utilization cases
Jenkins can be coordinated with various cloud
suppliers forvarious use cases like dynamic Jenkins slaves, Deploy to
cloudconditions. A portion of the cloud can be incorporated are AWS Purplis
h blue Google Cloud OpenStack
Q117) What are Docker volumes and
what sort of volume oughtto be utilized to accomplis h relentless
capacity
Docker volumes are the filesystem mount focuses
made byclient for a compartment or a volume can be utilized by numerous
holders, andthere are dis tinctive sorts of volume mount accessible void
dir, Post mount, AWSupheld lbs volume, Azure volume, Google Cloud (or) even
NFS, CIFS filesystems,so a volume ought to be mounted to any of the outer
drives to accomplis hdetermined capacity, in light of the fact that a
lifetime of records insidecompartment, is as yet the holder is available and
if holder is erased, theinformation would be lost.
Q118) What are the Artifacts
store can be incorporated withJenkins
Any sort of Artifacts vault can be coordinated with
Jenkins,utilizing either shell directions (or) devoted modules, some of them
are Nexus,Jfrog.
Q119) What are a portion of the
testing apparatuses thatcan be coordinated with Jenkins and notice their
modules
Sonar module – can be utilized to incorporate
testingof Code quality in your source code. Execution module – this can
beutilized to incorporate JMeter execution testing. Junit – to dis tribute
unit test reports. Selenium module – can be utilized to incorporate
withselenium for computerization testing.
Q120) What are the manufacture
triggers accessible inJenkins
Fabricates can be run physically (or) either can
naturallybe activated by various sources like Webhooks- The webhooks are API
calls from SCM, at whateverpoint a code is submitted into a vault (or)
should be possible for explicitoccasions into explicit branches. Gerrit code
survey trigger-Gerrit is an opensource codeaudit instrument, at whatever
point a code change is endorsed after auditconstruct can be activated.
Trigger Build Remotely – You can have remote contentsin any machine (or)
even AWS lambda capacities (or) make a post demand totrigger forms in
Jenkins. Calendar Jobs-Jobs can likewis e be booked like Cronoccupations.
Survey SCM for changes – Where your Jenkins searchesfor any progressions in
SCM for the given interim, if there is a change, amanufacture can be
activated. Upstream and Downstream Jobs-Where a construct can beactivated by
another activity that is executed already.
Q121) How to Version
controlDocker pictures
Docker pictures can be form controlled utilizing
Tags, whereyou can relegate the tag to any picture utilizing docker tag
order. Furthermore, on the off chance that you are pushing any
docker centerlibrary without labeling the default label would be doled
out which is mostrecent, regardless of whether a picture with the most
recent is available, itindicates that picture without the tag and
reassign that to the most recent pushpicture.
Q122) What is the utilization of
Timestamper module inJenkins
It adds Timestamp to each line to the comfort yield
of theassemble.
Q123) Why you ought not execute
an expand on ace
You can run an expand on ace in Jenkins , yet it is
n’tprudent, in light of the fact that the ace as of now has the duty of
planningassembles and getting incorporate yields with JENKINS_HOME index, so
on the offchance that we run an expand on Jenkins ace, at that point it
furthermore needsto manufacture apparatuses, and workspace for source code,
so it puts executionover-burden in the framework, if the Jenkins ace
accidents, it expands thedowntime of your fabricate and dis charge cycle.
Q124) What do the main benefits
of DevOps
With a single team composed of cross-functional
commentssimply working in collaboration, DevOps organizations container
produceincluding maximum speed, functionality, including innovation. Where
continuespecial benefits: Continuous software control. Shorter complexity
tomanage.
Q125) What are the uses of DevOps
tools
Gradle. Your DevOps device stack will need a
reliable buildtool. Git. Git is one from the most successful DevOps
tools,widely applied across the specific software industry. Jenkins. Jenkins
is thatgo-to DevOps automation toolfor many software community teams.
Bamboo. Docker. Kubernetes. Puppet Enterpris e. Ansible.
Q126) What is DevOps beginner
DevOps is a society which supports collaboration
betweenDevelopment including Operations Team to deploy key to increase
faster in anautomated & repeatable way. In innocent words, DevOps backside
is establis hed as an association of development and IT operations
includingexcellent communication and collaboration.
Q127) What is the roles and
responsibilities of the DevOpsengineer
DevOps Engineer manages with developers including
the ITsystem to manage the code releases. They are both developers cases
becomeinterested in deployment including practice settings or sysadmins who
convert apassion for scripting and coding more move toward the development
front whereall can improve that planning from test and deployment.
Q128) Which is the top DevOps
toolsand it’s Whichtools have you worked on
Dis cover about the trending Top DevOps Tools
including Git.Well, if you live considering DevOps being a toolwhen, you are
wrong! DevOpsdoes not a toolor software, it’s an appreciation that you can
adopt forcontinuous growth. file and, by practicing it you can simply
coordinate this work among your team.
Q129) Explain the typical
characters involved inDevOps
Commitment to the superior level in the
organization. Needfor silver to be delivered across the organization.
Version checksoftware. Automated tools to compliance to process.
AutomatedTesting Automated Deployment
Q130) What are your expectations
from a career perspectiveof DevOps
To be involved in the end to end delivery method
and themost important phase of helping to change the manner so as to allow
thatdevelopment and operations teams to go together also understand
eachother’s point of view.
Q131) What does configuration
management under terms likeinfrastructure further review some popular
tools used
In Software Engineering Software Configuration
Management is a unique task about tracking to make the setting configuration
during theinfrastructure with one change. It is done for deploying,
configuring andmaintaining servers.
Q132) How will you approach when
each design must toimplement DevOps
As the application is generated and deployed, we do
need tocontrolits performance. Monitoring means also really important
because it mightfurther to uncover some defects which might not have been
detectedearlier. Q133) Explain about from Continuous Testing From the above
goal of Continuous Integration which is totake this application excuse to
close users are primarily providing continuousdelivery. This backside is
completed out any adequate number about unit testingand automation testing.
Hence, we must validate that this system created andintegrated with all the
developers that work as required. Q134) Explain about from Continuous
Delivery. Continuous Delivery means an extension of ConstantIntegration
which primarily serves to make the features which some developerscontinue
developing out on some end users because soon as possible. During this
process, it passes through several stages of QA, Staging etc., and before
fordelivery to the PRODUCTION system.
Q135) What are the tasks also
responsibilities of DevOpsengineer
In this role, you’ll work collaboratively
includingsoftware engineering to use and operate our systems. Help automate
alsostreamline our procedures and processes. Build also maintain tools
fordeployment, monitoring, including operations. And troubleshoot and
resolveproblems in our dev, search and production environments.
Q136) What is defined DevOps
engineer should know
DevOps Engineer goes including developers and that
IT staffto manage this code releases. They live both developers who become
involvedthrough deployment including web services or sysadmins that become a
passion forscripting and coding more move into the development design where
only candevelop this planning from search also deployment.
Q137) How much makes any DevOps
engineer make
A lead DevOps engineer can get between $137,000
including$180,000, according to April 2018 job data of Glassdoor. The common
salary fromany lead DevOps engineer based at the Big Apple is $141,452.
Q138) What mean the specific
skills required for a DevOpsengineer
While tech abilities are a must, strong DevOps
engineersfurther possess this ability to collaborate, multi- task, also
always place thatcustomer first. critical skills that all DevOps engineer
requirements forsuccess.
Q139) What is DevOps also why is
it important
Implementing the new approach would take in many
advantageson an organization. A seamless collection up can be performed in
the teams ofdevelopers, test managers, and operational executives also hence
they can workin collaboration including each other to achieve a greater
output on aproject.
Q140) What is means by DevOps
lifecycle
DevOps means an agile connection between
developmentincluding operations. It means any process followed by this
development becausewell because of help drivers clean of this starting of
this design to productionsupport. Understanding DevOps means incomplete
excuse estimated DevOpslifecycle. Tools for an efficient DevOps workflow. A
daily workflowbased at DevOps thoughts allows team members to achieve
content faster, beflexible just to both experiments also deliver value, also
help each part fromthis organization use a learning mentality.
Q142) Can you make DevOps without
agile
DevOps is one about some key elements to assis t
you toachieve this . Can you do agile software evolution without doing
DevOps Butmanaging agile software development and being agile are a couple
reallydifferent things.
Q143) What exactly defined is
DevOps
DevOps is all of bringing commonly the structure
alsoprocess of traditional operations, so being support deployment,
including anytools, also practices of traditional construction methods so as
source controlalso versioning. Q144) Need for Continuous Integration:
Improves the quality of software. Reduction in time taken todelivery Allows
dev team to detect and locate problems early Q145) Success factor for the
Continuous Integration Maintain Code Repository Automate the build Perform
daily checkin and commits to baseline Test in cloneenvironment Keep the
build fast Make it easy to get the newest deliverables
Q146) Can we copy Jenkins job
from one server to otherserver
Yes, we can do that using one of the following ways
We can copy the Jenkins jobs from one server to other serverby copying the
corresponding jobs folder. We can make a copy of the exis ting jobby making
clone of a job directory with different names Rename the exis ting jobby
renaming the directory
Q147) How can we create the
backup and copy inJenkins
We can copy or backup, we need to backup
JENKINS_HOMEdirectory which contains the details of all the job
configurations, builddetails etc. Q148) Difference between “poll scm”
and“build periodically” Poll SCM will trigger the build only if it detects
thechange in SCM, whereas Build Periodically will trigger the build once the
giventime period is elapsed.
Q149) What is difference between
docker image and dockercontainer
Docker image is a readonly template that contains
theinstructions for a container to start. Docker container is a runnable
instanceof a docker image
Q150) What is Application
Containerization
It is a process of OS Level virtualization
technique used todeploy the application without launching the entire VM for
each applicationwhere multiple is olated applications or services can access
the same Host andrun on the same OS. Q151) syntax for building docker image
docker build –f -timagename:version Q152) running docker image
docker run –dt –restart=always –p : -h
-v : imagename:version
Q153) How to log into a container docker exec –it
/bin/bash
Q154) What is Puppet
Puppet is a Configuration Management tool, Puppet
is used toautomate adminis tration tasks.
Q155) What is Configuration
Management
Configuration Management is the System engineering
process.Configuration Management applied over the life cycle of a system
providesvis ibility and controlof its performance, functional, and
physicalattributesrecording their status and in support of Change
Management. Q156) Lis t the Software Configuration ManagementFeatures.
Enforcement Cooperating Enablement Version ControlFriendly Enable Change
ControlProcesses Q157) Lis t out the 5 Best Software Configuration
ManagementTools. CFEngine Configuration Tool. CHEF Configuration
ToolAnsibleConfiguration ToolPuppet Configuration Tool. SALTSTACK
Configuration Tool.
Q158) Why should Puppet be chosen
It has good community support Easy to Learn
Programming Language DSL It is opensource
Q159) What is Saltstack
SaltStack is based on Python programming &
Scripitinglanguage. Its also a configuration tool.Saltstack works on a
non-centralizedmodel or a master-client setup model. it provides a push and
SSH methods tocommunicate with clients.
Q160) Why should Puppet to be
chosen
There are Some Reason puppet to be chosen. Puppet
is opensource Easy to Learn Programming Language DSL Puppet has
goodcommunity support Q161) Advantages of VCS Multiple people can work on
the same project and it helps usto keep track of the files and documents and
their changes. We can merge the changes from multiple developers to
singlestream. Helps us to revert to the earlier version if the current
version is broke. Helps us to maintain multiple version of the software at
thesame location without rewriting. Q162) Advantages of DevOps Below are the
major advantages Technical: Continuous software delivery Less Complexity
Faster Resolution Business: Faster delivery of the features More stable
operatingenvironment Improved communication and collaboration between
variousteams Q163) Use cases where we can use DevOps Explain the legacy /
old procedures that are followed todevelop and deploy software Problems of
that approach How can we solve the above is sues using DevOps. For the 1 st
and2 nd points, development of theapplication, problems in build and
deployment, problems in operations, problemsin debugging and fixing the is
sues For 3 rd pointexplain various technologies we can use to ease the
deployments, fordevelopment, explain about taking small features and
development, how it helpsfor testing and is sue fixing. Q164) Major
difference between Agile and DevOps Agile is the set of rules/principles and
guidelines abouthow to develop a software. There are chances that this
developed software worksonly on developer’s environment. But to release that
software to publicconsumption and deploy in production environment, we will
use the DevOps toolsand Techniques for the operation of that software. In a
nutshell, Agile is the set of rules for the developmentof a software, but
DevOps focus more on Development as well as Operation of theDeveloped
software in various environments.
Q165) What Are the Benefits Of
Nosql
Non-relationals and schema-less data models Low
latency andhigh performance Highly scalable
Q166) What Are Adoptions Of
Devops In Industry
Use of the agile and other development processes
andmethods. Demand for an increased rate of the production releases
fromapplication and business. Wide availability of virtuals and cloud
infrastructurefrom both internal and external providers; Increased usage of
the data center,automation and configuration management tools; Increased
focus on the testautomation and continuous integration methods; Best
practices on the critical is sues.
Q167) How is the Chef Used As a
Cm Tool
Chef is the considered to be one of the
preferredindustry-wide CM tools. Facebook migrated its an infrastructure and
backend ITto the Chef platform, for example. Explain how to the Chef helps
you to avoiddelays by automating processes. The scripts are written in Ruby.
It canintegrate with a cloud-based platforms and configure new systems. It
providesmany libraries for the infrastructure development that can later to
be deployedwithin a software. Thanks to its centralized management system,
one of the Chefserver is enough to be used as the center for deploying
various policies.
Q168) Why Are the Configuration
Management Processes AndTools Important
Talk about to multiple software builds, releases,
revis ions,and versions for each other software or testware that is being
developed. Moveon to explain the need for storing and maintaining data,
keeping track of thedevelopment builds and simplified troubleshooting. Don’t
forget to mentionthat key CM tools that can be used to the achieve these
objectives. Talk abouthow to tools like Puppet, Ansible, and Chef help in
automating softwaredeployment and configuration on several servers.
Q169) Which Are the Some Of the
Most Popular Devops Tools The most popular DevOps tools included`
Selenium Puppet Chef Git Jenkins Ansible
Q170) What Are the Vagrant And
Its Uses
Vagrant used to virtual box as the hypervis or for
virtualenvironments and in current scenario it is also supporting the KVM.
Kernel-basedVirtual Machine. Vagrant is a toolthat can created and managed
environmentsfor the testing and developing software. Devops Training Free
Demo
Q171) How to Devops is Helpful To
Developers
To fix the bug and implements new features of the
quickly.It provides to the clarity of communications among team members.
Q172) Name of The Popular
Scripting Language Of the Devops
Python
Q173) Lis t of The Agile
Methodology Of the Devops
DevOps is a process Agile is the same as DevOps.
Separate group are framed. Itis problem solving. Developers managing
production DevOps is the development-driven release management
Q174) Which Are The Areas of
Devops Are Implemented
Production Development Creation of the productions
feedback and its development ITOperations development
Q175) The Scope For SSH
SSH is a Secure Shell which provides users with a
secure,encrypted mechanis m to log into systems and transfer files. To log
out the remote machine and worked on commandline. To secure encrypted of the
communications between two hostsover an insecure network.
Q176) What Are The Advantages Of
Devops With Respect To theTechnical And Business Perspective
Technical benefits Software delivery is continuous.
Reduces Complexity inproblems. Faster approach to resolve problems Manpower
is reduced. Business benefits High rate of delivering its features Stable
operating environments More time gained to Addvalues. Enabling faster
feature time to market
Q177) What Are The Core
Operations Of the Devops In TermsOf the Development And Infrastructure
The core operations of DevOps Application
development Code developing Code coverage Unit testing Packaging Deployment
With infrastructure Provis ioning Configuration Orchestration Deployment
Q178) What Are The Anti-patterns
Of Devops
A pattern is common usage usually followed. If a
pattern ofthecommonly adopted by others does not work for your organization
and youcontinue to blindly follow it, you are essentially adopting an
anti-pattern.There are myths about DevOps. Some of them include DevOps is a
process Agile equalsDevOps We need a separate DevOps group Devops will solve
all ourproblems DevOps means Developers Managing Production DevOps is
Development-driven release management DevOps is not development driven.
DevOps is not IT Operations driven. We can’t do DevOps– We’re Unique We
can’t do DevOps – We’re got the wrongpeople
Q179) What are The Most Important
Thing Devops Helps UsAchieve
The most important thing that the DevOps helps us
achieve is to get the changes into production as quickly as possible while
that minimizingris ks in software quality assurance and compliance. This is
the primaryobjective of DevOps. For example clear communication and better
workingrelationships between teams i.e. both of the Ops team and Dev team
collaboratetogether to deliver good quality software which in turn leads to
higher customersatis faction.
Q180) How Can Make a Sure New
Service is Ready For TheProducts Launched
Backup System Recovery plans Load Balancing
Monitoring Centralizedlogging
Q181) How to All These Tools Work
for Together
Given below is a generic logical of the flow
whereeverything gets are automated for seamless delivery. However, its flow
may varyfrom organization to the organization as per the requirement.
Developers develop the code and this source code is managedby Version
ControlSystem of the tools like Git etc. Developers send to this code of the
Git repository and anychanges made in the code is committed to this
Repository. Jenkins pulls this code from the repository using the Gitplugin
and build it using tools like Ant or Maven. Configuration managements tools
like puppet deploys &provis ions testing environment and then Jenkins
releases this code on the testto environment on which testing is done using
tools like selenium. Once the code are tested, Jenkins send it for the
deploymenton production to the server (even production server are provis
ioned &maintained by tools like puppet). After deployment Its continuously
monitored by tools likeNagios. Docker containers provides testing
environment to the testthe build features.
Q182) Which Are The Top Devops
Tools
The most popular DevOps tools are mentioned below
GitVersion ControlSystem tool Jenkins Continuous Integration toolSelenium
ContinuousTesting tool Puppet, Chef, Ansible are Configuration Management
andDeployment tools Nagios Continuous Monitoring tool Docker
Containerization tool
Q183) How to Devops Different
From the Agile / Sdlc
Agile are the set of the values and principles
about how toproduce i.e. develop software. Example if you have some ideas
and you want to the turnthose ideas into the working software, you can use
the Agile values areprinciples as a way to do that. But, that software might
only be working on developer’s laptop or in a test environment. Youwant a
way to quickly, easily and repeatably move that software into theproduction
infrastructure, in a safe and simple way. To do that you needs areDevOps
tools and techniques. You can summarize by saying Agile of the
softwaredevelopment methodology focuses on the development for software but
DevOps onthe other hand is responsible for the development as well as
deployment of thesoftware to the safest and most reliable way to the
possible. Here’s ablog that will give you more information of the evolutions
of the DevOps.
Q184) What is The Need For Devops
According to me, this should start by explaining
the generalmarket trend. Instead of the releasing big sets of the features,
companies aretrying to see if small features can be transported to their
customers through aseries of the release trains. This have many advantages
like quick feedback fromthe customers, better quality of the software etc.
which in turn leads to thehigh customer satis faction. To achieve this ,
companies are required to Increase deployment frequency Lower failure rate
of newreleases Shortened lead time between fixes Faster mean time to
recovery of the event of new releasecrashing
Q185) What is meant by Continuous
Integration
It’s the development practice that requires
developersto integrate code into a shared repository several times a day.
Each check-inthen verified by an automated build, allowing teams to the
detect problemsearly. Q186) Mention some of the useful plugins in Jenkins.
Below, I have mentioned some important are Plugins: Maven 2 project Amazon
EC2 HTML publis her Copy artifactJoin Green Balls
Q187) What is Version control
Its the system that records changes are the file or
set ofthe files over time so that you can recall specific versions later.
Q188) What are the uses of
Version control
Revert files back to a previous state. Revert to
the entireproject back to a previous state. Compare changes over time. See
who last modified the something that might to be causinga problem. Who
introduced an is sue and when.
Q189) What are the containers
Containers are the of lightweight virtualization,
heavierthan ‘chroot’ but lighter than ‘hypervis ors’. Theyprovide is olation
among processes
Q190) What is meant by Continuous
Integration
It is a development practice that requires are
developers tointegrate code into the shared repository several times a day.
Q191) What’s a PTR in DNS
Pointer (PTR) record to used for the revers DNS
(Domain NameSystem) lookup.
Q192) What testing is necessary
to insure a new service is ready for production
Continuous testing
Q193) What is Continuous Testing
It is the process of executing on tests as part of
thesoftware delivery pipelines to obtain can immediate for feedback is the
businessof the ris ks associated with in the latest build.
Q194) What is Automation Testing
Automation testing or Test Automation is a process
of theautomating that manual process to test the application/system under
test.
Q195) What are the key elements
of continuoustesting
Ris k assessments, policy analysis ,
requirementstraceabilities, advanced analysis , test optimis ation, and
servicevirtualis ations
Q196) What are the Testing types
supported bySelenium
Regression testing and functional testing Also
Read>> Top Selenium Interview Questions &Answers
Q197) What is Puppet
It is a Configuration Management toolwhich is used
to theautomate adminis tration of the tasks.
Q198) How does HTTP work
The HTTP protocolare works in a client and server
modellike most other protocols. A web browser using which a request is
initiated is called as a client and a web servers software which are the
responds to thatrequest is called a server. World Wide Web Consortium of the
InternetEngineering Task Force are two importants spokes are the
standardization of theHTTP protocol.
Q199) Describe two-factor
authentication
Two-factors authentication are the security process
in whichthe user to provides two means of the identification from separate
categories ofcredentials.
Q200) What is git add
adds the file changes to the staging area
Q201) What is git commit
Commits the changes to the HEAD (staging area)
Q202) What is git push
Sends the changes to the remote repository
Q203) What is git checkout
Switch branch or restore working files
Q204) What is git branch
Creates a branch
Q205) What is git fetch
Fetch the latest his tory from the remote server
and updatesthe local repo
Q206) What is git merge
Joins two or more branches together
Q207) What is git pull
Fetch from and integrate with another repository or
a localbranch (git fetch + git merge)
Q208) What is git rebase
Process of moving or combining a sequence of
commits to anew base commit
Q209) What is git revert
To revert a commit that has already been publis hed
and madepublic
Q210 What is git clone
Ans: clones the git repository and creates a
working copy inthe local machine
Q211) What is the difference
between the Annie Playbookbook and the characters
Roles The characters are a restructured entity of a
play. Playsare on playbooks. A set of functions to accomplis h the specific
role. Mapsbetween hosts and roles. Example: Common, Winners. Example:
site.yml,fooservers.yml, webservers.yml.
Q212) How do I see all the
ansible_ variables lis t
By naturally collecting “facts” about themachines,
these facts can be accessed in Playbooks and in templates. To see alis t of
all the facts about a computer, you can run a “setup” blockas an ad hoc
activity: Ansible -m system hostname It will print a dictionary of all the
facts available forthat particular host.
Q213) What is Doctor
Docax is a container technology that connects
yourapplication and all its functions into the form of containers to ensure
that youare running uninterrupted in any situation of your use.
Q214) What is the Tagore film
Tucker is the source of the dagger container. Or in
otherwords, dagger pictures are used to create containers.
Q215) What is the tooger
container
Dogger Container is a phenomenon of the film.
Q216) Do we consider Dev Devils
as a smart way
Of course, we !! The only difference between
dynamicalgorithms and DevObs is that the dynamic process is implemented for
thedevelopment section and activates both DevOps development
andfunctionality.
Q217) What are the benefits of
using Git
Data personality and copy Get high only one. A
directory directory in the repository High dis kusage and network
performance Joint friendship Git can use any kind of projects.
Q218) What is kernel
A kernel, the software that can easily change the
hardwareinterfaces of your computer.
Q219) What is the difference
between grep -i and grep-v
I accept this value L) ls | grep -i docker
Dockerfile docker.tar.gz ls | grep -v docker Desktop Dockerfile Documents
Downloads You can not find anything with name docker.tar.gz Q220) You can
define a specific location for thefile This feature is generally used to
give the server areplacement location. Let me tell you on the computer below
and I want to create1GB swap space, dd if = / dev / zero = = / swapfile1 bs
= 1G count =1
Q221) What is the concept of sudo
in Linux
Pseudo is an application for Unix-and Linux-based
systemsthat provide the ability to allow specific users to use specific
system commandsin the system’s root level.
Q222) What is Jenkins pipe
Jenkins pipeline (or simply “tube”) is anadditional
package that supports and activates continuous delivery tube inJenkins.
Q223) How to stop and restart the
toxin container
Stop container: stop container container ID Reboot
the Tucker Container now: Docer Re-containerID
Q224) Which sites are running by
Tagore
Docax is running on Linux and Cloud platforms only:
Ubuntu 12.04 LTS + Fedora 20+ RHEL 6.5+ CentOS 6+ Gentoo ArchLinux openSUSE
12.3+ CRUX 3.0+ Cloud: Amazon EC2 Google Compute Engine Microsoft Asur
Rackspace Since support is not supported, do not work on Windows orMac for
token production, yes, even on windows you can use it for testingpurposes
Q225) What are the tools used for
taxi networking
We usually use karfs and taxi bear to do
taxinetworking.
Q226) What does Tucker write
You would like to have a number of taxiers
containers, andat that time you need to create a file that creates a docer
and type the commandto make a taxi-up. It runs all containers mentioned in
the docer composefile.
Q227) What is a scrum
Using scrime based on your complex software and
productdevelopment task as small particles, it uses reboots and additional
procedures.Each replay is two weeks. Scrum has three characters: product
owner, scrummaster and team
Q228) Purpose for SSH
SSH is a secure shell that allows users to login to
asecure, encrypted mechanis m into computers and transmitting files.Exit
theremote machine and work on the command line. Protect encrypted
communications between the two hosts on anunsafe network.
Q229) Are DevOps implemented
Product development Creating product feedback and
its development IT ActivitiesDevelopment.
Q230) Do you want to lis t the
active modes ofDevOps
DevOps is a process Like the active DevOps. A
separate group is configured. This will solve theproblem. Manufacturers
manufacturing production DevOps is a development-driven output management
Q231) Do you lis t the main
difference between active andDevOffice
Agile: There is something about dynamic software
developmentDevops: DevOps is about software deployment and management.
DevOps does not replace the active or lean. By removingwaste, by removing
gloves and improving regulations, it allows the production ofrapid and
continuous products.
Q232) For the popular scripting
language of DevOps
Python
Q233) How does DevOps help
developers
To correct the defect and immediately make
innovativeattributes. This is the accuracy of the coordination between the
membersof the group.
Q234) What is Vegand and its Uses
Virtual virtual box has been used as a hyperversion
forvirtual environments and in the current scenario it supports KVM.
Kernel-basedvirtual machine Vegant is a toolfor creating and managing the
environmentfor making software and experiments. Tutorials Tutorial Free Demo
Q235) What is the main difference
between Linux and Unixoperating systems
Unix: It belongs to the multitasking, multiuser
operating systemfamily. These are often used on web servers and
workstations. It was originally derived from AT & T Unix, which wasstarted
by the Bell Labs Research Center in the 1970s by Ken Thompson, Dennis
Ritchie, and many others. Operating systems are both open source, but the
comparis onis relatively similar to Unix Linux. Linux: Linux may be familiar
to each programming language. Thesepersonal computers are used. The Unix
operating system is based on the kernel.
Q236) How can we ensure how to
prepare a new service forthe products launched
Backup system Recovery plans Load balance
TrackingCentralized record
Q237) What is the benefit of
NoSQL
Independent and schema-less data model Low latency
and highperformance Very scalable Q238) What is the adoption of Devokos in
theprofession 1. Use of active and other developmental processes andmethods.
An increased ratio of production output is required from useand business.
Virtual and Cloud Infrastructure Transfers from Internal andOutdoor
Providers; Increased use of data center, automation and
configurationmanagement tools; Focusing on testing automation and serial
coordinationsystems; Best Practices in Important Problems
Q239) What are the benefits of
NoSQL database onRDBMS
Benefits: ETL is very low Support for structured
text is provided Changes in periodsare handled Key Objectives Function. The
ability to measure horizontally Many data structures areprovided. Vendors
may be selected. Q240) The first 10 capabilities of a person in the
positionof DevOp should be. The best in system adminis tration
Virtualizationexperience Good technical skills Great script Good development
skills Chef in the automation toolexperience Peoplemanagement Customer
service Real-time cloud movements Who’s worried aboutwho
Q241) What is PTR in DNS
The PNS (PTR) regis tration is used to turn the
search DNS(Domain Name System).
Q242) What do you know about
DevOps
Your answer should be simple and straightforward.
Start byexplaining the growing importance of DevOps in information
technology.Considering that the efforts of the developments and activities
to acceleratethe delivery of software products should be integrated, the
minimum failurerate. DevOps is a value-practical procedure in which the
design and performanceengineers are able to capture the product level or
service life cycle across thedesign, from design and to the design level
Q243) Why was Dev’s so important
in the past fewyears
Before dis cussing the growing reputation of
DevOps, dis cussthe current industry scenario. The big players like Netflix
and Facebook beginwith some examples of how this business can help to
develop and use unwantedapplications. Facebook’s continuous use and coding
license models, and howto measure it, while using Facebook to ensure the
quality of the experience.Hundreds of lines are implemented without
affecting ranking, stability andsecurity. Dipops Training Course Your next
application must be Netflix. This streaming andon-the-video video company
follows similar procedures with complete automatedprocesses and systems.
Specify user base of these two companies: Facebook has 2billion users,
Netflix provides online content for more than 100 million usersworldwide.
Reduced lead time between the best examples of bugs, bugfixes, runtime and
continuous supplies and the overall reduction of humancosts.
Q244) What are some of the most
popular DevOpstools
The most popular DevOps tools include: Selenium
Puppet Chef Git information Jenkins Ansible Tucker Tipps Online Training
Q245) What is Version Control,
and why should VCSuse
Define the controlbar and talk about any changes to
one ormore files and store them in a centralized repository. VCS Tools
remembersprevious versions and helps to: Make sure you do not go through
changes over time. Turn on specific files or specific projects to the
olderversion. Explore the problems or errors of a particular change. Using
VCS, developers provide flexibility to worksimultaneously on a particular
file, and all changes are logicallyconnected.
Q246) is There a Difference
Between Active and DevOpsIfyes, please explain
As a DevOps Engineer, interview questions like this
are verymuch expected. Start by explaining the clear overlap between DevOps
and Agile.Although the function of DevOps is always synonymous with dynamic
algorithms,there is a clear difference between the two. Agile theories are
related to thesoft product or development of the software. On the other
hand, DevOps is handled with development, ensuring quick turnaround times,
minimal errors andreliability by installing the software continuously.
Q247) Why are structural
management processes and toolsimportant
Talk about many software developments, releases,
edits andversions for each software or testware. Describe the need for data
storage andmaintenance, development of developments and tracking errors
easily. Do notforget to mention key CM tools that can be used to achieve
these goals. Talkabout how the tools, such as buffet, aseat, and chef are
useful in automatingsoftware deployment and configuration on multiple
servers.
Q248) How is the chef used as a
CM tool
Chef is considered one of the preferred
professional CMTools. Facebook has changed its infrastructure and the Shef
platform keeps trackof IT, for example. Explain how the chef helps to avoid
delays by automatingprocesses. The scripts are written in ruby. It can be
integrated intocloud-based platforms and configures new settings. It
provides many librariesfor infrastructure development, which will then be
installed in a software.Thanks to its centralized management system, a chef
server is sufficient to usevarious policies as the center of ordering.
Q249) How do you explain the
concept of“Infrastructure Index” (IAC)
This is a good idea to talk about IAC as a
concept,sometimes referred to as a programming program, where the
infrastructure is similar to any other code. The traditional approach to
managing infrastructureis how to take a back seat and how to handle manual
structures, unusual toolsand custom scripts Q250) Lis t the essential DevOps
tools. Git information Jenkins Selenium Puppet Chef Ansible Nagios
LaborerMonit El-Elis torsch, Lestastash, Gibbon Collectd / Collect Git
Information (Gitwidia)
Q251) What are the main
characters of DevOps engineersbased on growth and infrastructure
DevOps Engineer’s major work roles
ApplicationDevelopment Developing code Code coverage Unit testing Packaging
Preparing with infrastructure Continuous integrationContinuous test
Continuous sorting Provis ioning Configuration OrchestrationDeployment
Q252) What are the advantages of
DevOps regarding technicaland business perspective
Technical Advantages: Software delivery continues.
Problems reduce austerity. Fast approach to solving problems Humans are
falling. Business Benefits: The higher the rate for its features Fixed
operatingsystems It took too long to add values. Run fast time for themarket
Learn more about DevOps benefits from this informationblog.
Q253) Purpose for SSH
SSH is a secure shell that allows users to login to
asecure, encrypted mechanis m into computers and transmitting files. Exit
the remote machine and work on the command line. Protect encrypted
communications between the two hosts on anunsafe network.
Q254) Which part of DevOps is
implemented
Product development Creating product feedback and
its development IT ActivitiesDevelopment Q255) Lis t the DevOps’s active
algorithm. DevOps is a process Like the active DevOps. A separate group is
configured. This will solve theproblem. Manufacturers manufacturing
production DevOps is a development-driven output management Q256) Lis t the
main difference between active anddevOps. Agile: There is something about
dynamic software developmentDevops: DevOps is about software deployment and
management. DevOps does not replace the active or lean. By removingwaste, by
removing gloves and improving regulations, it allows the production ofrapid
and continuous products. Q257) For the popular scripting language of DevOps.
Python
Q258) How does DevOps help
developers
Correct the error and activate new features
quickly. It provides clarity of clarity between the members of thegroup.
Q259) What is the speed and its
benefits
Virtual virtual box has been used as a hyperversion
forvirtual environments and in the current scenario it supports KVM.
Kernel-basedvirtual machine Vegant is a toolfor creating and managing the
environmentfor making software and experiments.
Q260) What is the use of Anuj
It is mainly used for information technology
infrastructureto manage or use applications for remote applications. We want
to sort an app onthe nodes of 100 by executing one command, then the
animation is actually in thepicture, but you need to know or run some
knowledge on the animatedscript.
Q1.What is Infrastructure as Code
Answer: Where the Configuration of any servers or
toolchainor application stack required for an organization can be made into
moredescriptive level of code and that can be used for provis ioning
andmanage infrastructure elements like Virtual Machine, Software,
NetworkElements, but it differs from scripts using any language, where
theyare series of static steps coded, where Version controlcan be used
inorder to track environment changes.Example Tools are Ansible,Terraform.
Q2.What are the areas the Version
controlcan introduce toget efficient DevOps practice
Answer: Obviously the main area of Version
Controlis Sourcecode management, Where every developer code should be pushed
to the commonrepository for maintaining build and release in CI/CD
pipelines.Another area canbe Version controlFor Adminis trators when they
use Infrastructure as A Code(IAC) tools and practices for maintaining The
Environment configuration.AnotherArea of Version Controlsystem Can be
Artifactory Management Using Repositorieslike Nexus & DockerHub.
Q3.Why the Opensource tools boost
DevOps
Answer: Opensource tools predominantly used by
anyorganization which is adapting (or) adopted DevOps pipelines because
devops camewith the focus of automation in various aspects of organization
build andrelease and change management and also infrastructure
managementareas.
So developing or using a single toolis impossible
andalso everything is basically trial and error phase of development and
also agilecuts down the luxury of developing a single tool, so
opensource tools wereavailable on the market pretty much saves every
purpose and also givesorganization an option to evaluate the toolbased
on their need.
Q4.What is the difference between
Ansible and chef(or)puppet
Answer: Ansible is Agentless configuration
management tool,where puppet or chef needs agent needs to be run on the
agent node and chef orpuppet is based on pull model, where your cookbook or
manifest for chef andpuppet respectively from the master will be pulled by
the agent and ansible usesssh to communicate and it gives data-driven
instructions to the nodes need to bemanaged , more like RPC execution,
ansible uses YAML scripting, whereas puppet(or) chef is built by ruby uses
their own DSL .
Q5.What is folder structure of
roles in ansible
Answer: roles common tasks handlers files templates
varsdefaults meta webservers tasks defaultsmeta/
Where common is role name, under tasks– there will be tasks (or) plays
present, handlers – to hold thehandlers for any tasks, files – static
files for copying (or) moving toremote systems, templates- provides to
hold jinja based templating , vars– to hold common vars used
byplaybooks.
Q6. What is Jinja2 templating in
Ansible playbooks and theiruse
Answer: Jinja2 templating is the Python standard
fortemplating , think of it like a sed editor for Ansible , where it can be
used is when there is a need for dynamic alteration of any config file to
anyapplication like consider mapping a MySQL application to the IP address
of themachine, where it is running, it cannot be static , it needs altering
itdynamically at runtime .
Format
{{ foo.bar}}
The vars within the {{ }} braces are replaced by ansiblewhile running
using templatemodule.
Q7. What is the need for
organizing playbooks as the role,is it necessary
Answer: Organizing playbooks as roles , gives
morereadability and reusability to any plays , while consider a task where
MySQLinstallation should be done after the removal of Oracle DB , and
anotherrequirement is needed to install MySQL after java installation, in
both cases weneed to install MySQL , but without roles need to write
playbooks separately forboth use cases , but using roles once the MySQL
installation role is created canbe utilis ed any number of times by invoking
using logic in site.yaml.
No, it is not necessary to create roles for
every scenario,but creating roles is a best practice inAnsible.
Q8.What is main dis advantage of
Docker containers
Answer: As the lifetime of any containers is while
runningafter a container is destroyed you cannot retrieve any data inside a
container,the data inside a container is lost forever, but persis tent
storage for datainside containers can be done using volumes mount to an
external source likehost machine and any NFS drivers.
Q9. What are docker engine and
docker compose
Answer: Docker engine contacts the docker daemon
inside themachine and creates the runtime environment and process for any
container,docker composes links several containers to form as a stack used
in creatingapplication stacks like a LAMP, WAMP,XAMP.
Q10. What are the Different modes
does a container can berun
Answer: Docker container can be run in two modes
Attached:Where it will be run in the foreground of the system you are
running, provides aterminal inside to container when -t option is used with
it, where every logwill be redirected to stdout screen. Detached: This mode
is usually run inproduction, where the container is detached as a background
process and everyoutput inside the container will be redirected log files
inside/var/lib/docker/logs/<container-id>/<container-id.json>and
which can be viewed by docker logs command.
Q11. What the output of docker
inspect command willbe
Answer: Docker inspects <container-id>
willgive output in JSON format, which contains details like the IP address
of thecontainer inside the docker virtual bridge and volume mount
information andevery other information related to host (or) container
specific like theunderlying file driver used, log driver used. docker
inspect [OPTIONS] NAME|ID[NAME|ID…] Options
Name, shorthand
DefaultDescription
— format, -f Format the output using the given
Gotemplate
–size , -s Dis play total file sizes if the type is
container
–type Return JSON for specified type
Q12.What is the command can be
used to check the resourceutilization by docker containers
Answer: Docker stats command can be used to check
theresource utilization of any docker container, it gives the output
analogous toTop command in Linux, it forms the base for container resource
monitoring toolslike advis or, which gets output from docker stats command.
docker stats[OPTIONS] [CONTAINER…] Options
Name, shorthand
DefaultDescription
— all, -a Show all containers (default shows
justrunning)
–format Pretty-print images using a Gotemplate
–no-stream Dis able streaming stats and only pull thefirst result
–no-trunc Do not truncate output
Q13.What is the major difference
between Continuosdeployment and continuos delivery
Answer: Where continuos deployment is fully
automated anddeploying to production needs no manual intervention in
continuos deployment,whereas in continuos delivery the deployment to
production has some manual intervention for change management in
Organizationfor better management, and it needs to approved by manager or
higher authoritiesto be deployed in production. According to your
application ris k factor fororganization, the continuos deployment (or)
delivery approach will be chosen.
Q14.How to execute some task (or)
play on localhost onlywhile executing playbooks on different hosts on an
ansible
Answer: In ansible, there is a module called
delegate_to, inthis module section provide the particular host (or) hosts
where your tasks (or)task need to be run. tasks:
– name: ” Elasticsearch Hitting”
uri:url='{{ url2 }}_search
Q=status:new’headers='{“Content-type”:”application/json”}’method=GET
return_content=yes regis ter: output delegate_to: 127.0.0.1
Q15. What is the difference
between set_fact and vars inansible
Answer: Where a set_fact sets the value for a
factor at onetime and remains static, even though the value is Quite dynamic
and vars keep on changing as per the valuekeeps on changing for the
variable. tasks: – set_fact: fact_time:“Fact: {{lookup(‘pipe’,
‘date\”+%H:%M:%S\”‘)}}” – debug: var=fact_time –command: sleep 2 – debug:
var=fact_time tasks: – name: lookups invariables vs. lookups in facts hosts:
localhost vars: var_time: “Var:{{lookup(‘pipe’, ‘date\”+%H:%M:%S\”‘)}}” Even
though the lookup for date hasbeen used in both the cases , where in the
vars is used it alters based on thetime to time every time executed within
the playbook lifetime. But Fact alwaysremains same once lookup is done
Q16. What is the lookup in
ansible and what are lookupplugins supported by ansible
Answer: Lookup plugins allow access of data in
Ansible fromoutside sources. These plugins are evaluated on the Ansible
controlmachine, andcan include reading the filesystem but also contacting
external datastores andservices. Format is
{lookup{‘<plugin>’,’<source(or)connection_string>’}}Some of the
lookup plugins supported by ansible are File pipe redis jinjatemplates etcd
kv store …
Q17. How can you delete the
docker images stored on yourlocal machine and how can you do it for all
the images at once
Answer: The command docker rmi <image-id>
canbe used to delete the docker image from local machine , whereas some
images mayneed to be forced because the image may be used by some other
container (or)another image , to delete images you can use the combination
of commands bydocker rmi $(docker images - Q) , where docker images will
give the docker image names ,to get only the ID of docker images only , we
are using - Q switch with docker images command.
Q18. What are the folders in the
Jenkins installation andtheir uses
Answer: JENKINS_HOME – which will
be/$JENKINS_USER/.jenkins it is the root folder of any Jenkins installation
and itcontains subfolders each for different purposes. jobs/ – Folder
containsall the information about all the jobs configured in the Jenkins
instance.Inside jobs/, you will have the folder created for each job and
inside thosefolders, you will have build folders according to each build
numbers each buildwill have its log files, which we see in Jenkins web
console. Plugins/ –where all your plugins will be lis ted. Workspace/ – this
will be present to hold all theworkspace files like your source code pulled
from SCM.
Q19. What are the ways to
configure Jenkins system
Answer: Jenkins can be configured in two ways Web:
Wherethere is an option called configure system , in there section you can
make allconfiguration changes . Manual on filesystem: Where every change can
also bedone directly on the Jenkins config.xml file under the Jenkins
installationdirectory , after you make changes on the filesystem, you need
to restart yourJenkins, either can do it directly from terminal (or) you can
use Reloadconfiguration from dis k under manage Jenkins menu or you can hit
/restartendpoint directly.
Q20. What is the role Of HTTP
REST API in DevOps
Answer: As Devops is purely focuses on Automating
yourinfrastructure and provides changes over the pipeline for different
stages likean each CI/CD pipeline will have stages like
build,test,sanitytest,UAT,Deployment to Prod environment as with each stage
there are differenttools is used and different technology stack is presented
and there needs to bea way to integrate with different toolfor completing a
series toolchain, therecomes a need for HTTP API , where every
toolcommunicates with different toolsusing API , and even user can also use
SDK to interact with different tools likeBOTO for Python to contact AWS
API’s for automation based on events ,nowadays its not batch processing
anymore , it is mostly event drivenpipelines
Q21. What are Microservices, and
how they power efficientDevOps practices
Answer: Where In traditional architecture ,
everyapplication is monolith application means that anything is developed by
a groupof developers , where it has been deployed as a single application in
multiplemachines and exposed to outer world using loadbalancers , where
themicroservices means breaking down your application into small pieces ,
whereeach piece serves the different functionality needed to complete a
singletransaction and by breaking down , developers can also be formed to
groups andeach piece of application may follow different guidelines for
efficientdevelopment phase , because of agile development should be phased
up a bit andevery service uses REST API (or) Message Queues to communicate
between other service. So build andrelease of a non-robust version may not
affect whole architecture , instead somefunctionality is lost , that
provides the assurance for efficient and fasterCI/CD pipelines and DevOps
Practices
Q22. What are the ways that a
pipeline can be created inJenkins
Answer: There are two ways of the pipeline can be
created inJenkins Scripted Pipelines: More like a programming approach
Declarativepipelines: DSL approach specifically for creating Jenkins
pipelines. Thepipeline should be created in Jenkins file and the location
can either be in SCMor local system. Declarative and Scripted Pipelines are
constructedfundamentally differently. Declarative Pipeline is a more recent
feature ofJenkins Pipeline which: Provides richer syntactical features over
ScriptedPipeline syntax, and is designed to make writing and reading
Pipeline codeeasier.
Q23. What are the Labels in
Jenkins & where it canbe utilis ed
Answer: As with CI/CD solution needs to be
centralized ,where every application in the organization can be built by a
single CI/CDserver , so in organization there may be different kinds of
application likejava , c#,.NET and etc , as with microservices approach your
programming stackis loosely coupled for the project , so you can have Labels
in each node and select the optionOnly built jobs while label matching this
node , so when a build is scheduledwith the label of the node present in it
, it waits for next executor in thatnode to be available , eventhough there
are other executors in nodes.
Q24. What is the use of Blueocean
in Jenkins
Answer: Blue Ocean rethinks the user experience of
Jenkins.Designed from the ground up for Jenkins Pipeline, but still
compatible withfreestyle jobs, Blue Ocean reduces clutter and increases
clarity for everymember of the team. It provides sophis ticated UI to
identify each stage of thepipeline and better pinpointing for is sues and
very rich Pipeline editor forbeginners.
Q25. What is the callback plugins
in ansible, give someexamples of some callback plugins
Answer: Callback plugins enable adding new
behaviors toAnsible when responding to events. By default, callback plugins
controlmost ofthe output you see when running the command line programs, but
can also be usedto add additional output, integrate with other tools and
marshall the events toa storage backend. So whenever an play is executed and
after it produces someevents , that events are printed onto Stdout screen
,so callback plugin can beput into any storage backend for log processing.
Example callback plugins areansible-logstash, where every playbook execution
is fetched by logstash in theJSON format and can be integrated any other
backend source likeelasticsearch.
Q26. What are the scripting
languages can be used inDevOps
Answer: As with scripting languages , the basic
shellscripting is used for build steps in Jenkins pipelines and python
scripts can beused with any other tools like Ansible , terraform as a
wrapper script for someother complex decis ion solving tasks in any
automation as python is moresuperior in complex logic derivation than shell
scripts and ruby scripts canalso be used as build steps in Jenkins.
Q27. What is Continuos Monitoring
and why monitoring is verycritical in DevOps
Answer: Devops brings out every organization
capablity ofbuild and release cycle to be much shorter with concept of CI/CD
, where everychange is reflected into production environments fastly , so it
needs to betightly monitored to get customer feedbacks. So the concept of
continuosmonitoring has been used to evaluate each application performance
in real time(atleast Near Real Time) , where each application is developed
with applicationperformance monitor agents compatible and the granular level
of metrics aretaken out like JVM stats and even fuctional wis e metrics
inside the applicationcan also be poured out in real time to Agents , which
in turn gives to anybackend storage and that can be used by monitoring teams
in dashboards andalerts to get continuosly monitor the application
Q28. Give some examples of
continuos monitoringtools
Answer: Where many continuos monitoring tools are
availablein the market, where used for a different kind of application and
deploymentmodel Docker containers can be monitored by cadvis or agent ,
which can be usedby Elasticsearch to store metrics (or) you can use TICK
stack (Telegraf,influxdb,Chronograf,Kapacitor) for every systems monitoring
in NRT(Near RealTime) and You can use Logstash (or) Beats to collect Logs
from system , which inturn can use Elasticsearch as Storage Backend can use
Kibana (or) Grafana asvis ualizer. The system monitoring can be done by
Nagios and Icinga.
Q29. What is docker swarm
Answer: Group of Virtual machines with Docker
Engine can beclustered and maintained as a single system and the resources
also being sharedby the containers and docker swarm master schedules the
docker container in anyof the machines under the cluster according to
resource availability Dockerswarm init can be used to initiate docker swarm
cluster and docker swarm joinwith the master IP from client joins the node
into the swarm cluster.
Q30. What are the ways to create
Custom Dockerimages
Answer: Docker images can be created by two ways
broadlyDockerfile: Most used method , where base image can be specified and
the filescan be copied into the image and installation and configuration can
be doneusing declarative file which can be given to Docker build command to
produce newdocker image. Docker commit: Where the Docker image is pinned up
as aDocker container and every command execute inside a container forms a
Read-onlylayer and after every changes is Done can use docker
commit<container-iD> to save as a image, although this method is
notsuitable for CI/CD pipelines , as it re Quires manual intervention.
Q31. Give some important
directives in Dockerfile and anexample Dockerfile
Answer: FROM – Gives the base image to use. RUN–
this directive used to run a command directly into any image. CMD- Torun the
command, but the format of command specification is more arguments basedthan
a single command like RUN. ADD (or) COPY – To copy files from yourlocal
machine to Docker images you create. ENTRYPOINT- Entrypoint command keepsthe
command without execution, so when the container is spawned from an
image,the command in entry point runs first. Example Dockerfile FROM
python:2 MAINTAINER janakiraman RUN mkdir /code ADD test.py /code
ENTRYPOINT[“python”,”/code/test.py”] Q32. Give some important Jenkins
Plugins Answer: SSH slaves plugin
PipelinePlugin
Github Plugin
Email notificationsplugin
Docker publis h plugin
Mavenplugin
Greenball plugin
Q33.What is the use of vaults in
ansible
Answer: Vault files are encrypted files, which
contains anyvariables used by ansible playbooks, where the vault encrypted
files can bedecrypted only by the vault-password, so while running a
playbook, if any vaultfile is used for a variable inside playbooks, so need
to used–-ask-vault-pass command argument while running playbook.
Q34. How does docker make
deployments easy
Answer: Docker is a containerization technology,
which is aadvanced technology over virtualization, where in virtualization,
an applicationneeds to be installed in machine , then the OS should be spin
up and spinning upVirtual machine takes lot time , and it divides space from
Physical hardware andhypervis or layer wastes vast amount of space for
running virtual machines andafter it is provis ioned, Every application
needs to be installed andinstallation re Quires all dependencies and
sometimes dependencies may mis sout even if you double check and migration
from machine to machine ofapplications is painful , but docker shares
underlying OS resources , wheredocker engine is lightweight and every
application can be packaged withdependency once tested works everywhere
same, migration of application orspinning up of new application made easy
because just needs to install onlydocker in another machine and docker image
pull and run does all the magic ofspinning up in seconds.
Q35. How .NET applications can be
built usingJenkins
Answer: .NET applications needs Windows nodes to
built ,where Jenkins can use Jenkins windows slave plugin can be used to
connectwindows node as a Jenkins slave , where it uses DCOM connector for
Jenkinsmaster to slave connection (or) you can use Jenkins JNLP connector
and the Buildtools and SCM tools used for the pipeline of .NET application
needs to beinstalled in the Windows slave and MSBuild build toolcan be used
to build .NETapplication and can be Deployed into Windows host by using
Powershell wrapperinside Ansible playbooks.
Q36. How can you make a High
available Jenkins master-mastersolution without using any Jenkins plugin
Answer: Where Jenkins stores all the build
information inthe JENKINS_HOME directory , which can be mapped to any NFS
(or) SAN storagedrivers , common file systems and when the node is down ,
can implement amonitoring solution using Nagios to check alive , if down can
trigger an ansibleplaybook (or) python script to create a new Jenkins master
in different node andreload at runtime, if there is already a passive
Jenkins master in anotherinstance kept silent with same JENKINS_HOME Network
file store.
Q37. Give the structure of
Jenkins file
Answer: Jenkins filed starts with Pipeline
directive ,inside the pipeline directive will be agent directive , which
specifies wherethe build should be run and next directive would be stages ,
which containsseveral lis t of stage directives and each stage directive
contains differentsteps . There are several optional directives like options
, which providescustom plugins used by the projects (or) any other
triggering mechanis ms usedand environment directive to provide all env
variables Sample Jenkins filepipeline{ agent any stages {
stage(‘Dockerbuild’) { steps { sh“sudo docker build. -t pyapp:v1” } } } }
Q38. What are the uses of
integrating cloud withDevOps
Answer: The centralized nature of cloud computing
providesDevOps automation with a standard and centralized platform for
testing,deployment, and production.Most cloud providers gives Even DevOps
technologieslike CI tools and deployment tools as a service like codebuild,
codepipeline,codedeploy in AWS makes easy and even faster rate of DevOps
pratice.
Q39. What is Orchestration of
containers and what are thedifferent tools used for orchestration
Answer: When deploying into production, you cannot
use asingle machine for production as it is not robust for any deployment ,
so whenan application is containerized, the stack of applications maybe run
at singledocker host in development environment to check application
functionality, whilewhen we arrive into production servers, that it is not
the case, where youshould deploy your applications into multiple nodes and
stack should beconnected between nodes , so to ensure network connectivity
between differentcontainers , you need to have shell scripts (or) ansible
playbooks betweendifferent nodes ,and another dis advantage is using this
tools , you cannot runan efficient stack, where an application is taking up
more resources in one node, but another sits idle most time , so deployment
strategy also needs to beplanned out according to resources and
load-balancing of this applications alsobe configured, so to clear out all
this obstacles , there came a concept calledorchestration , where your
docker containers is orchestrated between differentnodes in the cluster
based on resources available according to schedulingstrategy and everything
should be given as DSL specific files not like scripts.There are Different
Orchestration tools available in market which areKubernetes,Swarm,Apache
Mesos.
Q40. What is ansible tower
Answer: Ansible is developed by Redhat , which
provides ITautomation and configuration management purposes. Ansible Tower
is the extendedmanagement layer created to manage playbooks organization
using roles andexecution and can even chain different number of playbooks to
form workflows.Ansible tower dashboard provides NOC-style UI to look into
the status of allansible playbooks and hosts status.
Q41. What are the programming
language applications that canbe built by Jenkins
Answer: Jenkins is a CI/CD toolnot depends on
anyProgramming language for building application, if there is a build toolto
builtany language, that’s enough to build, even though plugin for build
toolnot available, can use any scripting to replace your build stage like
Shell,Powershell, Python scripts to make build of any language application.
Q42. Why is every toolin DevOps
is mostly has some DSL(Domain Specific Language)
Answer: DevOps is culture developed to address the
needs ofagile methodology , where the developement rate is faster ,so
deployment shouldmatch its speed and that needs operations team to
co-ordinate and work with devteam , where everything can automated using
script-based , but it feels morelike operations team than , it gives messy
organization of any pipelines , morethe use cases , more the scripts needs
to be written , so there are several usecases, which will be ade Quate to
cover the needs of agile are taken and tools arecreated according to that
and customiztion can happen over the toolusing DSL toautomate the DevOps
practice and Infra management.
Q43. What are the clouds can be
integrated with Jenkins andwhat are the use cases
Answer: Jenkins can be integrated with different
cloudproviders for different use cases like dynamic Jenkins slaves, Deploy
to cloudenvironments. Some of the clouds can be integrated areAWS
Azure
GoogleCloud
OpenStack
Q44. What are Docker volumes and
what type of volume shouldbe used to achieve persis tent storage
Answer: Docker volumes are the filesystem mount
pointscreated by user for a container or a volume can be used by many
containers , andthere are different types of volume mount available empty
dir, Post mount, AWSbacked lbs volume, Azure volume, Google Cloud (or) even
NFS, CIFS filesystems,so a volume should be mounted to any of the external
drive to achieve persis tentstorage , because a lifetime of files inside
container , is till the containeris present and if container is deleted, the
data would be lost.
Q45. What are the Artifacts
repository can be integratedwith Jenkins
Answer: Any kind of Artifacts repository can be
integratedwith Jenkins, using either shell commands (or) dedicated plugins,
some of themare Nexus, Jfrog.
Q46. What are the some of the
testing tools that can beintegrated with jenkins and mention their
plugins
Answer: Sonar plugin – can be used to
integratetesting of Code Quality in your source code. Performance plugin –
this can be used to integrate JMeter performance testing. Junit – to publis
hunit test reports. Selenium plugin – can be used to integrate withselenium
for automation testing.
Q47. What are the build triggers
available inJenkins
Answer: Builds can be run manually (or) either
canautomatically triggered by different sources like Webhooks– The
webhooksare API calls from SCM , whenever a code is committed into
repository (or) canbe done for specific events into specific branches.
Gerrit code reviewtrigger– Gerrit is an opensource code review tool,
whenever a code changeis approved after review build can be triggered.
Trigger Build Remotely –You can have remote scripts in any machine (or) even
AWS lambda functions (or)make a post re Quest to trigger builds in Jenkins.
Schedule Jobs- Jobs canalso schedule like Cron jobs. Poll SCM for changes –
Where your Jenkinslooks for any changes in SCM for given interval, if there
is a change, the buildcan be triggered. Upstream and Downstream Jobs– Where
a build can betriggered by another job that is executed previously.
Q48. How to Version controlDocker
images
Answer: Docker images can be version controlled
using Tags ,where you can assign tag to any image using docker tag
<image-id>command. And if you are pushing any docker hub regis try
without tagging thedefault tag would be assigned which is latest , even if a
image with the latestis present , it demotes that image without tag and
reassign that to the latestpush image.
Q49. What is the use of
Timestamper plugin inJenkins
Answer: It adds Timestamp to every line to the
consoleoutput of the build.
Q50.Why should you not execute a
build on master
Answer: You can run a build on master in Jenkins ,
but it is not advis able , because the master already has the responsibility
of schedulingbuilds and getting build outputs into JENKINS_HOME directory
,so if we run abuild on Jenkins master , then it additionally needs to build
tools, andworkspace for source code , so it puts performance overload in the
system , ifthe Jenkins master crashes , it increases the downtime of your
build and releasecycle.
Q51. Why devops
Answer: DevOps is the market trend now, which
follows asystematic approach for getting the application live to market.
DevOps is allabout tools which helps in building the development platform as
well asproduction platform. Product companies are now looking at a Code as a
serviceconcept in which the development skill is used to create a
productionarchitecture with atmost no downtime.
Q52. Why Ansible
Answer: A Configuration Management toolwhich is
agentless.It works with key based or password based ssh authentication.
Since it is agentless, we have the complete controlof the manipulating data.
Ansible is also use for architecture provis ioning as it has modules which
can talk to majorcloud platforms. I have mainly used for AWS provis ioning
and application/systemconfig manipulations.
Q53. Why do you think a Version
controlsystem is necessaryfor DevOps team
Answer: Application is all about code, if the UI is
notbehaving as expected, there could be a bug in the code. Inorder to track
thecode updates, versioning is a must. By any chance if bug breaks the
application, we should beable to revert it to the working codebase.
Versioning helps to achievethis . Also, by keeping a track of code commits
by individuals, itis very easy to find the source of the bug in the code.
Q54. What role would you prefer
to be in the DevOpsteam
Answer: Basically the following are prominent in
DevOpsdepending upon the skillset. Architect Version ControlPersonnel
Configuration controlTeam Build and Integration management Deployment Team.
Testing People QA Q55. Architecture Monitoring Team Answer: In my opinion,
everyone should owe to be anarchitech. with this course, I will be fir the
role from 2 to 5. Everyone shouldunderstand the working of each role. Devops
is a collective effort ratherindividual effect.
Q56. Suppose you are put in to a
project where you have toimplement devops culture, what will be your
approach
Answer: Before thinking of DevOps, there should be
a clearcut idea on what need to be implement and it should be done by the
Seniorarchitect. If we take a simple example of shopping market : Output of
this business will be a website which dis playsonline shopping items, and a
payment platform for easy payment. Even though it looks simple, the
background work is not thateasy, because a shopping cart must be : – 99.99%
live Easy and fast processing of shopping items Easy and fast payment
system. – Quick reporting to shopkeeper – Quick Inventory Management Fast
customer interaction and many more DevOps has to be implement in each
process and phase. Nextis the tools used for bringing the latest items in
website with minimal timespan. Git, Jenkins, Ansible/Chef, AWS can be much
of familiar tools with helpsin continuous delivery to market.
Q57. Whether continuous
deployment is possiblepractically
Answer: Ofcourse it is possible if we bring the
Agility inevery phase of development and deployment. The release, testing
and deploymentautomation should be so accurately finetuned
Q58. What is Agility in devops
basically
Answer: Agile is an iterative form of process
whichfinalizes the application by fulfilling the checklis t. For any
process, thereshould be set of checklis t inorder to standardize the code as
well as the buildand deployment process. The lis t depends on the
architecture of the applicationand business model.
Q59. Why scripting using Bash,
Python or any other languageis a must for a DevOps team
Answer: Even though we have numerous tools in
devops, butthere will certain custom re Quirements for a project. In such
cases, we have to make useof scripting and then integrate it with the tools.
Q60. In AWS, how do you implement
high availability ofwebsites
The main concept of high availability is that the
websiteshould be live all the time. So we should avoid single point of
failure, inorderto achieve this LoadBalancer can be used. In AWS, we can
implement HA with LBwith AutoScaling methods.
Q61.How to debug inside a docker
container
Answer: The feature “docker exec” allows usersto
debug a container
Q62.What do you mean by Docker
Engine
It is open source container build and management
tool
Q63.Why we need Docker
Answer: Applications were started to use Agile
methodologywhere they build and deployed iteratively . Docker helps is
deploying same binaries with dependenciesacross different environments with
fraction of seconds
Q64.What do you mean by Docker
daemon
Answer: Docker Daemon Receives and processes
incoming API reQuests from the CLI .
Q65.What do you mean by Docker
client
Answer: Command line tool– which is a docker
binaryand it communicate to the Docker daemon through the Docker API.
Q66.what do you mean by Docker
Hub Regis try
Answer: It is a Public image regis try maintanined
by Dockeritself and the Docker daemon talks to it through the regis try API
Q67.How do you install docker on
a debian Linux OS
Answer: sudo apt-get install docker.io
Q68.What access does docker group
have
Answer: The docker user have root like access and
we shouldrestrict access as we would protect root
Q69.How to lis t the packages
installed in Ubuntu container
Answer: dpkg -l lis ts the packages installed in
ubuntucontainer
Q70.How can we check status of
the latest runningcontainer
Answer: With “docker ps -l” commandlis t
latest running processes
Q71.How to Stop a container
Answer: “docker kill “command to kill acontainer
“docker stop “command to stop a container
Q72.How to lis t the stopped
containers
Answer: docker ps -a ( –an all)
Q73.What do you mean by docker
image
Answer: An image is a collection of files and its
meta data, basically those files are the root filesystem of the container
Image is madeup of layers where each layer can be edited Q74.What is the
differences between containers andimages Answer: An image is an read-only
filesystem where containeris a running form of an image . Image is
non-editable and on containers we can edit as wewis h & save that again
to a new image
Q75.How to do changes in a docker
image
Answer: No we can’t do changes in an image. we
canmake changes in a Dockerfile or to the exis ting container to create a
layerednew image
Q76.Different ways to create new
images
Answer: docker commit: to create an image from a
containerdocker build: to create an image using a Dockerfile
Q77.Where do you store and manage
images
Answer: Images can be stored in your local docker
host or ina regis try .
Q78.How do we download the images
Answer: Using “docker pull” command we candownload
a docker image
Q79. What are Image tags
Answer: Image tags are variants of Docker image
.“latest” is the default tag of an image
Q80.What is a Dockerfile.
Answer: A Dockerfile series of instructions to
build adocker image Docker build command can be used to build
Q81.How to build a docker file
Answer: docker build -t <image_name>
Q82.How to view hostory of a
docker image
Answer: The docker his tory command lis ts all the
layers inan image with image creation date, size and command used
Q83.What are CMD and ENTRYPOINT
Answer: These will allow using the default command
to beexecuted when a container is starting
Q84.EXPOSE instruction is used
for
Answer: The EXPOSE command is used to publis h
ports of adocker container
Q85.What is Ansible
Answer: A configuration management toolsimilar to a
puppet, chef etc .
Q86.Why to choose Ansible
Answer: Ansible is simple and light where it needs
only shhand python as a dependency . It doesnt re Quired an agent to be
installed
Q87.What are the ansible modules
Answer: Ansible “modules” are pre-defined smallset
of codes to perform some actions eg: copy a file, start a service
Q88.What are Ansible Tasks
Answer: Tasks are nothing but ansible modules with
thearguments
Q89.What are Handlers in ansible
Answer: Handlers are triggered when there is need
in changeof state e.g.restart service when a property file have changed.
Q90.What are Roles in ansible
Answer: Roles are re-usable tasks or handlers.
Q91.What is YAML
Answer: YAML – yet another markup language is way
ofstoring data in a structured text format like JSON
Q92.What are Playbooks
Answer: Playbooks are the recipes to ansible
Q93.What is MAVEN
Answer: Maven is a Java build tool, so you must
have Javainstalled to proceed.
Q94.What do you mean by validate
in maven
Answer: Validate is to check whether the info
provided arecorrect and all necessary is available
Q95.What do you mean by compile
in maven
Answer: It is to compile the source code of
theproject
Q96.What do you mean by test in
maven
Answer: It is to test the source code to test using
suitabletesting framework
Q97.What do you mean by package
in maven
Answer: It is to do the binary packaging of the
compiledcode
Q98.What is docker-compose
Answer: Compose is to define and run a
multi-containerapplication
Q99.What is Continuous
integration
Answer: CI is nothing but giving immediate feedback
to thedeveloper by testing , analyzing the code .
Q100. What is Continuous delivery
Answer: Continuous delivery is a continuation of CI
whichaims in delivering the software until pre -prod automatically
Q101.What is Continuous
deployment
Answer: Continuous deployment is next step after CI
and CDwhere the tested software will be provide to the end customers post
somevalidation and change management activities
Q102.What is git
Answer: git is a source code version management
system.
Q103.What is git commit
Answer: git commit records changes done to file in
the localsystem.
Q104.what is git push
Answer: git push is to update the changes to the
remoterepository in the internet .
Q105.What’s git fetch
git fetch will pull only the data from the remote
repo butdoesnt merge with the repo in your local system.
Q106.What is git pull
Answer: git pull will download the files from the
remoterepo and will merge with the files in your local system.
Q107.How to reset the Last git
Commit
Answer: “git reset” command can be used to undolast
commit .
Q108.What is the need for DevOps
Answer: Start the answer by explaining general
market trend,how releasing small features benefits compared to releasing big
features,advantages of releasing small features in high fre Quency. Dis cuss
about the topics such as Increase deploymentfre Quency
Lower failure rate of newerreleases
Reduced time for bug fixes
Timeto recovery
Q109. Write the key components of
DevOps
Answer: These are te key comonents of DevOps.
ContinuousIntegration
ContinuousTesting
Continuous Delivery
ContinuousMonitoring
Q110. What are the various tools
used in DevOps
Answer: DevOps contains various stages. Each stage
can beachieved with various tools. Below are the various toolthat are
popularly usedtools in DevOps. Version Control: Git , SVN
CI/CD :Jenkins
Configuration Management Tools : Chef, Puppet,Ansible
Containerization Tool: Docker
Also mention any other tools that you worked on that helped you to
automate theexis ting environment
Q111. What is Version Control
Answer: Version ControlSystem (that are made to the
filesor documents over a period of time.
Q112. What are the types of
Version ControlSystems
Answer: There are two types of Version
ControlSystems:Central Version ControlSystem, Ex: Git,Bitbucket
Dis tributed/Decentralized Version ControlSystem
Q113. What is jenkinsIn jenkins,
what is the programminglanguage should be used
Answer: It is a open Source automation tool. it is
a puposeof Continuous Integration and Continuous Delivery. Jenkins is a
written in javaProgramming language. Q114. Give an explanation about DevOps.
Answer: DevOps is nothing but a practice that emphasizes thecollaboration
and communication of both software developers and implementationteam. It
focuses on delivering software product faster and lowering the failurerate
of releases.
Q115. What are the key Principles
or Aspects behindDevOps
Answer: The key Principles or Aspects are
Infrastructure ascode
Continuousdeployment
Automation
Monitoring
Security
Q116. Describe the core operations of DevOps withInfrastructure and
with application. Answer: The core operations of DevOps are
InfrastructureProvis ioning
Configuration
Orchestration
Deployment
Application development Code building
Codecoverage
Unittesting
Packaging
Deployment
Q117. How “Infrastructure code”
is processed orexecuted in AWS
Answer: In AWS, Infrastructure code will be in
simple JSONformat After that JSON code will be organized into files called
templates You can Implement the templates on AWS DevOps and thenmanaged as
stacks At last the creating, deleting, updating, etc. operation inthe stack
are done by Cloud Formation
Q118. Which scripting language is
most important for aDevOps engineer
Answer: It is very important to choose the simplest
languagefor DevOps engineer. Python Language is most suitable language
forDevOps.
Q119. How DevOps helps developers
Answer: Developers can fix bug and implement new
featureswith less time by the help of DevOps. DevOps can also help to build
a perfectcommunication system in a team with every team member.
Q120. Which are popular tools for
DevOps
Answer: Popular tools for DevOps areJenkins
Nagios
Monit
ELK(Elasticsearch, Logstash,Kibana)
Jenkins
Docker
Ansible
Git
Q121. What is the usefulness of
SSH
Answer: SSH is used to log into a remote machine
and work onthe command line and also used it to dig into the system to make
possible securecoded communications between two untrusted hosts over an
insecurenetwork.
Q122. How you would handle revis
ion (version)control
Answer: I will post the code on SourceForge or
GitHub togive avis ual for everyone. I will post the checklis t also from
the last revis ionto make sure that any unsolved is sues are resolved.
Q123. How many types of Http re
Quests are
Answer: The types of Http re Quests are GET
HEAD
PUT
POST
PATCH
DELETE
TRACE
CONNECT
OPTIONS
Q124.If a Linux-build-server
suddenly starts getting slowwhat will you check
Answer: If a Linux-build-server suddenly starts
gettingslow, I will check for following three things Application Level
troubleshooting:is sues related with RAM, is sues related with Dis k I/O
read write, is sues relatedwith Dis k space, etc. System-Level
troubleshooting: Check for Application logfile OR application server log
file, system performance is sues, Web Server Log– check HTTP, tomcat log,
etc. or check jboss, WebLogic logs to see if theapplication server
response/receive time is the is sues for slowness, Memory Leakof any
application Dependent Services troubleshooting: is sues related
withAntivirus, is sues related with Firewall, Network is sues, SMTP server
responsetime is sues, etc Q125. Describe the key components of DevOps. The
most important DevOps components are: ContinuousIntegration
ContinuousTesting
Continuous Delivery
ContinuousMonitoring
Q126. Give example of some popular cloud platform used forDevOps
Implementation. Answer: For DevOps implementation popular Cloud
platformsare: Google Cloud
Amazon WebServices
Microsoft Azure
Q127. Describe benefits of using Version Controlsystem. Answer:
Version Controlsystem gives scope to team membersto work on any file at
suitable time. All the previous versions and variants areclosely packed up
inside the VCS. You can use dis tributed VCS to store the complete
projecthis tory in case central server breakdown you can use your team
member’sfile location storage related with the project. You can see the
actual changes made in the file’scontent.
Q128. How Git Bis ect helps
Answer: Git bis ect helps you to find the commit
whichintroduced a bug using binary search.
Q129. What is the build
Answer: Build is a method in which you can put
source codetogether for checking that is the source code working as a single
unit. In thebuild creation process, the source code will undergo
compilation, inspection,testing, and deployment.
Q130. What is Puppet
Answer: Puppet is a project management toolwhich
helps youto convert the adminis tration tasks automatically.
Q131.What is two-factor
authentication
Answer: Two-factor authentication is a security
method inwhich the user provides two ways of identification from
separatecategories.
Q132. What is ‘Canary Release’
Answer: It is a pattern which lowers the ris k of
new versionsoftware introduction into the production environment. User will
get“Canary Release” in a controlled manner before making it availableto the
complete user set.
Q133.What are the important types
of testing re Quired toensure new service is ready for production
Answer: You need to run continuous testing to make
sure thenew service is ready for production.
Q134. What is Vagrant
Answer: Vagrant is a toolused to create and manage
avirtual version of computing environments for tests and
softwaredevelopment. Q135. Usefulness of PTR in DNS. Answer: PTR or Pointer
record is used for reverse DNSlookup.
Q136. What is Chef
Answer: Chef is a powerful automation platform used
fortransforming infrastructure into code. In this tool, you can use write
scriptsthat are used to automate processes. Q137. Prere Quis ites for the
implementation of DevOps. Answer: Following are the useful prere Quis ites
for DevOps Implementation: At least one VersionControlSoftware (VCS).
Establis h communication between theteam members
Automated testing
Automateddeployment
Q138. For DevOps success which
are the bestpractices
Answer: Here, are essential best practices for
DevOpsimplementation: The speed of delivery means time taken for any task to
get theminto the production environment.
Track the defects are foundin the various
It’s important to calculate the actualor the average time taken to
recover in case of a failure in the productionenvironment.
Get a feedback from the customer about bugreport because it also affects
the Quality of application.
Q139. How SubGit toolhelps
Answer: SubGit helps you to move SVN to Git. You
can build awritable Git mirror of a local or alien to Subversion repository
by usingSubGit. Q140. Name some of the prominent network monitoringtools.
Answer: Some most prominent network monitoring tools are:Splunk
Icinga2
Wireshark
Nagios
OpenNMS
Q141. How do you know if your
video card can run UnityAnswer: When you use a command
1 /usr/lib/Linux/unity_support_test- p it will give
detailed output about Unity’s re Quirements, and if they are met, then your
video card canrun unity.
Q142. How to enable startup sound
in Ubuntu
Answer: To enable startup sound Click controlgear
and thenclick on Startup Applications In the Startup Application Preferences
window,click Add to add an entry Then fill the information in comment boxes
like Name,Command, and Comment 1 /usr/bin/canberra-gtk-
play—id=“desktop-login”—description= “play login sound”Logout and then login
once you are done You can use shortcut key Ctrl+Alt+T toopen .
Q143. Which is the fastest way to
open an Ubuntu terminal ina particular directory
Answer: To open an Ubuntu terminal in a
particulardirectory, you can use custom keyboard short cut. To do that, in
the commandfield of a new custom keyboard, type genome – terminal – –working
– directory = /path/to/dir.
Q144. How could you get the
current colour of the currentscreen on the Ubuntu desktop
Answer: You have to open the background image in
The Gimp(image editor) and use the dropper tool to select the colour on a
selectedpoint. It gives you the RGB value of the colour at that point.
Q145. How can you create
launchers on a desktop inUbuntu
Answer: You have to use ALT+F2 then
type”gnome-desktop-item-edit –create-new~/desktop,” it will launch theold
GUI dialog and create a launcher on your desktop in Ubuntu.
Q146. Explain what Memcached is
Answer: Memcached is an open source and
free,high-performance, dis tributed memory object caching system. The
primaryobjective of Memcached is to increase the response time for data
otherwis e itcan be recovered or constructed from some other source or
database. Memcached is used to reduce the necessity of S QL database
operation or another source repetitively tocollect data for a simultaneous
re Quest. Memcached can be used for SocialNetworking->Profile Caching
Content Aggregation -> HTML/ Page Caching
Ad targeting ->Cookie/profile tracking
Relationship -> Sessioncaching
E-commerce -> Session and HTMLcaching
Location-based services - > Database Query scaling
Gaming and entertainment-> Session caching
Memcache helps in Makeapplication processes much faster
Memcached make the objectselection and rejection process
Reduce the number ofretrieval re Quests to the database
Cuts down the I/O( Input/Output) access (hard dis k)
Drawback of Memcachedis It is not a preserving data store
Not adatabase
It is not an applicationspecific
Unable to cache largeobject
Q147. Mention some important
features of Memcached
Answer: Important features of Memcached includes
CAS Tokens:A CAS token is attached to an object retrieved from a cache. You
can use thattoken to save your updated object.
Callbacks: It simplifiesthe code
getDelayed: It decrease the time consumption ofyour script, waiting for
results to come back from aserver
Binary protocol: You can use binary protocolinsteadof ASCII with the
newer client
Igbinary: A client always hasto do serialization of the value with
complex data previously, but now withMemcached, you can use igbinary
option.
Q148. is it possible to share a
single instance of aMemcache between multiple projects
Answer: Yes, it is possible to share a single
instance ofMemcache between multiple projects. You can run Memcache on more
than one serverbecause it is a memory store space. You can also configure
your client to speakto a particular set of case. So, you can run two
different Memcache processes onthe same host independently.
Q149. You are having multiple
Memcache servers, one of thememcache servers fails, and it has your
data, can you recover key data from theperticular failed server
Answer: Data won’t be removed from the server
butthere is a solution for auto-failure, which you can configure for
multiplenodes. Fail-over can be triggered during any socket or Memcached
server levelerrors and not during standard client errors like adding an exis
ting key,etc.
Q150. How can you minimize the
Memcached serveroutages
Answer: If you write the code to minimize cache
stampedesthen it will leave a minimal impact
Another way is to bringup an instance of Memcached on a new machine
using the lost machines IPaddress
The code is another option to minimize serveroutages as it gives you the
liberty to change the Memcached server lis t withminimal work
Setting timeout value is another option thatsome Memcached clients
implement for Memcached server outage. When yourMemcached server goes
down, the client will keep trying to send a re Quest till the time-out
limit is reached
Q151. How can you update
Memcached when data changes
Answer: When data changes you can update Memcached
byClearing the Cache proactively: Clearing the cache when an insert or
update is made Resetting the Cache: this method is similar with previousone
but without delete the keys and wait for the next re Quest for the data to
refresh the cache, reset the valuesafter the insert or update.
Q152. What is Dogpile effectWhat
is the prevention of this effect
Answer: When a cache expires, and websites are hit
by themultiple re Quests made by the client at the same time the
Dogpileeffect occurs. You have to use semaphore lock to prevent the effect.
In this system after value expires, the first process ac Quires the lock and
starts generating new value.
Q153. How Memcached should not be
used
Answer: You have to use Memcached as cache; don’t
useit as a data store.
Don’t use Memcached as theultimate source of information to run your
application. You must always have anoption of data source in your hand.
Memcached is basically avalue store and can’t perform a Query over the
data or go through again over the contents toextract information.
Memcached is not secure either inencryption or authentication.
Q154. When a server gets shut
down does data stored inMemcached is still available
Answer: No after a server shuts down and then
restart thestored data in Memcached will be deleted because Memcached is
unable to storedata for long time.
Q155. What are the difference
between Memcache andMemcached
Answer: Memcache: It is an extension that allows
you to workthrough handy object-oriented (OOP’s) and procedural interfaces.
It is designed to reduce database load in dynamic webapplications.
Memcached: It is an extension that uses thelibmemcached library to
provide API for communicating with Memcached servers. Itis used to
increase the dynamic web applications by reducing database load. Itis
the latest API.
Q156. Explain Blue/Green Deployment Pattern Answer: Blue/Green
colouring pattern is one of the hardestchallenge faced at the time of
automatic deployment process. In Blue/ GreenDeployment approach, you need to
make sure two identical productionenvironments. Only one among them is LIVE
at any given point of time and it is called Blue environment. After take the
full preparation to release the software theteam conducts the final testing
in an environment called Green environment. Whenthe verification is complete
the traffic is routed to the Greenenvironment.
Q157. What are the containers
Answer: Containers are from of lightweight
virtualizationand create separation among process.
Q158. What is post mortem meeting
with reference toDevOps
Answer: In DevOps Post mortem meeting takes place
to dis cussabout the mis takes and how to repair the mis takes during the
totalprocess.
Q159. What is the easiest method
to build a smallcloud
Answer: VMfres is one of the best options to built
IaaScloud from Virtual Box VMs in lesser time. But if you want lightweight
PaaS,then Dokku is a better option because bash script can be PaaS out of
Dokkucontainers. Q160. Name two tools you can use for dockernetworking.
Answer: You can use Kubernetes and Docker swarm tools fordocker networking.
Q161. Name some of DevOps Implementation area Answer: DevOps are used for
Production, Production feedback,IT operation, and its software development.
Q162. What is CBD’
Answer: CBD or Component-Based Development is a uni
Que way to approach product development. In this method,Developers don’t
develop a product from scratch, they look for exis tingwell defined, tested,
and verified components to compose and assemble them to aproduct. Q163.
Explain Pair Programming with reference toDevOps Answer: Pair programming is
an engineering practice ofExtreme Programming Rules. This is the process
where two programmers work on thesame system on the same
design/algorithm/code. They play two different roles inthe system. One as
a“driver” and other as an “observer”.Observer continuously observes the
progress of a project to identify problems.T hey both can change their roles
in a step of theprogram.
Q1). Describe what DevOps is
DevOps is the new buzz in the IT world, swiftly
spreadingall through the technical space. Like other new and popular
technologies, peoplehave contradictory impressions of what DevOps is
exactly. The main objective ofDevOps is to alter and improve the
relationship between the development and ITteams by advocating better
inter-communication and smoother collaborationbetween two units of an
enterpris e.
Q2). What is the programming
language used in DevOps
Python is used in DevOps.
Q3). What is the necessity of
DevOps
Corporations are now facing the necessity of
carryingquicker and improved requests to see the ever more persis tent
demands of mindfulusers to decrease the “Time to Marketplace.“ DevOps often
benefitsplacement to occur very profligately.
Q4). Which are the areas where
DevOps is implemented
By the passage of time, the need for DevOps is
continuouslyincreasing. However, these are the main areas it is implemented
in- Areas of Production Development areas productionfeedback development of
IT Operations
Q5). What is agile expansion and
Scrum
Agile growth used as a substitute for Waterfall
developmenttraining. In Agile, the expansion process is more iterative and
additive; thereare more challenging and response at every stage of
development as opposed toonly the latter stage in Waterfall. Scrum is used
to accomplis h compositesoftware and product growth, using iterative and
additive performs. Scrum hasthree roles: Product owner Scrum master Team
Q6). Name a few most famous
DevOps tools
The most prevalent DevOps tools are stated below:
Puppet Chef Ansible Git Nagios DockerJenkins
Q7). Can we consider DevOps as an
agile practice
Yes, DevOps is considered as an agile practice
wheredevelopment is driven by profound changing demands of professionals to
stickcloser to the corporate needs and requirements
Q8). What is DevOps engineer’s
responsibilityconcerning Agile development
DevOps specialis t exertion very methodically with
Agiledevelopment teams to assurance they have a condition essential to
supportpurposes such as automatic testing, incessant Integration, and
unceasingDelivery. DevOps specialis t must be in continuous contact with the
developersand make all compulsory parts of environment work flawlessly.
Q9). Why is Incessant Testing
significant for DevOps
You can respond to this question by saying,
“IncessantTesting permits any change made in the code to be tested directly.
This circumvents the glitches shaped by having “big-bang” testingleft-hand
to the end of the series such as announcement postponements andquality
matters. In this way, Incessant Testing eases more recurrent and goodclass
releases.”
Q10). What do you think is the
role of SSH
SSH is a Secure Shell which gives the users a very
secure aswell encrypted mechanis m to safely log into systems and ensures
the safetransfer of files. It aids in the process of logging out of a remote
machinealong with the work on the command line. It helps in securing an
encrypted andprotected end to end communications between two hosts
communicating over aninsecure network.
Q11). How will you differentiate
DevOps from Agile
Agile is the technology which is all about
softwaredevelopment, whereas DevOps is the technology used for software
deployment andmanagement.
Q12). What are the benefits of
DevOps when seen from theTechnical and Business viewpoint
The Technical assis tance features of DevOps can be
givenas: Software delivery is incessant. Decreases Difficulty inproblems.
Quicker approach to resolve problems Workforce is abridged. Business welfare
features: A high degree of bringing its features Steady
operatingenvironments More time increased to Add values. Allowing quicker
feature time to market
Q13). Why do you think DevOps is
developers friendly
DevOps is developers friendly because it fixes the
bugs andimplements the new features very smoothly quickly. It is amazing
because itprovides the much-needed clarity of communication among team
members.
Q14). What measures would you
take to handle revis ion(version) control
To manage a successful revis ion control, you are
required topost your code on SourceForge or GitHub so that everyone on the
team can view itfrom there and also there is an option for viewers to give
suggestions for thebetter improvement of it. Q15). Lis t a few types of HTTP
requests. A few types of Http requests are” GET HEAD PUT POST PATCH DELETE
TRACECONNECT OPTIONS Q16). Explain the DevOps Toolchain. Here is the DevOps
toolchain- Code Build Test Package Release ConfigureMonitor Q17). Elucidate
the core operations of DevOps concerningdevelopment and Infrastructure. Here
is a lis t of the core operations of DevOps: Unit testing Packaging Code
coverage Code developing Configuration Orchestration Provis ioningDeployment
Q18). Why do you think there is a
need for ContinuousIntegration of Development & Testing
Continuous Integration of Development and Testing
enhancesthe quality of software and highly deducts the time which is taken
to deliverit, by replacing the old-schoolpractice of testing only after
completing allthe development process. Q19). Name a few branching strategies
used in DevOps A few branching strategies to be used are- Feature Branching
Task Branching Release Branching
Q20). What is the motive of GIT
tools in DevOps
Read: What is the Difference between Agile and
DevOps The primary objective of Git is to efficaciously manage aproject or a
given bundle of files as they keep on changing over time. Git toolstores
this important information in a data structure kind of thing called a
Gitrepository.
Q21). Explain what the major
components of DevOpsare
The major components of DevOps are continuous
integration,continuous delivery, continuous integration, and continuous
monitoring.
Q22). What steps should be taken
when Linux-based-serversuddenly gets slow
When a Linux-based-server suddenly becomes slow,
then youshould focus on three things primarily: Application level
troubleshooting System leveltroubleshooting Dependent level troubleshooting
Q23). Which cloud platforms can
be used for the successfulDevOps implementation
Cloud platforms that can be used for the successful
DevOpsimplementation are given as: Google Cloud Amazon Web Services
Microsoft Azure
Q24). What is a Version
ControlSystem (VCS)
VCS is a software application that helps software
developersto work together and maintain the complete his tory of their work.
Q25). What are the significant
benefits of VCS (VersionControlSystem)
The significant benefits of using VCS can be
givenas: It allows team members to work simultaneously. All past variants
and versions are packed within VCS. A dis tributed VCS helps you to store
the complete his tory ofthe project. In case of a breakdown of the central
server, you may use the localGIT repository.
It allows you to see what exact
changes are made to thecontent of a file. Q26). What is a Git Bis ect
Git Bis ect helps you to find the commit which
introduced abug using the binary search. Here is the basic syntax for a Git
Bis ect: Gitbis ect
Q27). What do you understand by
the term build
A build is a method in the source code where the
source codeis put together to check how it works as a single unit. In the
complete process,the source code will undergo compilation, testing,
inspection, anddeployment.
Q28). As per your experience,
what is the most importantthing that DevOps helps to achieve
The most important thing that DevOps helps us to
achieve is to get the changes in a product quickly while minimizing ris ks
related tosoftware quality and compliance. Other than this , there are more
benefits ofDevOps that include better communication, better collaboration
among teammembers, etc. Q29). Dis cuss one use case where DevOps can be
implementedin the real-life. Etsy is a Company that focuses on vintage,
handmade, anduniquely manufactured items. There are millions of Etsy users
who are sellingproducts online. At this stage, Etsy decided to follow a more
agile approach.DevOps helped Etsy with a continuous delivery pipeline and
fully automateddeployment lifecycle. Q30). Explain your understanding of
both the softwaredevelopment side and technical operations side of an
organization you haveworked in the past recently. The answer to this
question may vary from person to person.Here, you should dis cuss the
experience of how flexible you were in your lastCompany. free DevOps demo
DevOps Interview Questions and Answers for advancedworkforce In this
section, we will be dis cussing interview questionsfor experienced people
having more than three years of experience. Before you gothrough questions
directly, take this quiz first to become a little moreconfident in your
skills.
Q31). What are the anti-patterns
in DevOps
A pattern is used by others, not by organizations
and youcontinue blindly follow it. You are essentially adopting
anti-patternshere.
Q32). What is a Git Repository
It is a version controlsystem that tracks changes
to a fileand allows you to revert to any particular changes.
Q33). In Git, how to revert a
commit that has already beenmade public
Remove or fix the commit and push it to the
remoterepository. This is the most natural style to fix an error. To do this
, youshould use the command given below: Git commit –m “commitmessage”
Create a new commit that undergoes all changes that weremade in the bad
commit. Git revert
Q34). What is the process to
squash last N number of commitsinto a single commit
There are two options to squash last N number of
commitsinto a single commit. To write a new commit message from scratch, you
should usethe following command: git reset –soft HEAD ~N && git commit To
edit the exis ting message, you should extract thosemessages first and pass
them to the Git commit for later usage. Git reset–soft HEAD ~ N&& git commit
–edit –m “$(git log–format=%B –reverse .HEAD {N})”
Q35). What is Git rebase and how
to use it for resolvingconflicts in a feature branch before merging
Git Rebase is a command that is used to merge
another branchto the exis ting branch where you are working recently. It
moves all localcommits at the top of the his tory of that branch. It
effectively replays thechanges of feature branch at the tip of master and
allowing conflicts to beresolved in the process. Moreover, the feature
branch can be merged to the masterbranch with relative ease and sometimes
considered as the fast-forwardoperation.
Q36). How can you configure a git
repository to run codesanity checking tools right before making commits
and preventing them if thetest fails
Sanity or smoke test determines how to continue the
testingreasonably. This is easy configuring a Git repository to run code
sanitychecking before making commits and preventing them if the test fails.
It can bedone with a simple script as mentioned below: #!/bin/sh file=$(git
diff -cached -name-only -diff-filter=ACM | grep'.go$') if [ -z file]; then
exit 0 fi unfmtd=$(gofmt -I $files) if [ -z unfmtd]; then exit 0 fi eacho
"some .go files are not fmt'd" exit1
Q37). How to find a lis t of
files that are changed in acertain manner
To get a lis t of files that are changed or
modified in aparticular way, you can use the following command: git
diff-tree -r{hash}
Q38). How to set up a script
every time a repositoryreceives new commits from a push
There are three techniques to set up a script every
time arepository receives new commits from Push. These are the pre-receive
hook,post-receive hook, and update hook, etc. Q39). Write commands to know
in Git if a branch is merged tothe master or not. Here are the commands to
know in Git if a branch is mergedto the master or not. To lis t branches
that are merged to the current branch,you can use the following command: git
branch -merged To lis t branches that are not merged to the current
branch,you can use the following command: git branch – no-merged
Q40). What is continuous
integration in DevOps
It is a development practice that requires
developers tointegrate code into a shared repository multiple times a day.
Each check-in is verified with an automated build allowing teams to detect
problems early.
Q41). Why is continuous
integration necessary for thedevelopment and testing team
It improves the quality of software and reduces the
overalltime to product delivery, once the development is complete. It allows
thedevelopment team to find and locate bugs at an early stage and merge them
to theshared repository multiple times a day for automating testing.
Q42). Are there any particular
factors included incontinuous integration
These following points you should include to answer
this question: Automate the build and maintain a code repository. Make
thebuild self-tested and fast. Testing should be done in a clone of the
productionenvironment. It is easy getting the latest deliverables.
Automate the deployment, and
everyone should be able tocheck the result of the latest build. Q43).
What is the process to copy Jenkinsfrom one server to another
There are multiple ways to copy Jenkins from one
server toanother. Let us dis cuss them below: You can move the job from one
Jenkin installation to anotherby simply copying the corresponding job
directory. Make a copy of the exis ting job and save it with a differentname
in the job directory.
Rename the exis ting job and make
necessary changes as perthe requirement. Q44). How to create a file and
take backups in Jenkins
For taking backup in Jenkins, you just need to copy
thedirectory and save it with a different name. Q45). Explain the process to
set up jobs in Jenkins. Go to the Jenkins page at the top, select the
“newjob” option, and choose “Build a free-style softwareproject.” Select the
optional SCM where your source coderesides. Select the optional triggers to
controlwhen Jenkinsperforms builds. Choose the preferable script that can be
used to make thebuild. Collect the information for the build and notify
peopleabout the build results. Q46). Name a few useful plugins in Jenkins.
Some popular plugins in Jenkins can be given as:
Read: What is GitGit Tutorial
Guide for Beginners Maven 2project
Amazon EC2 HTML publis her Copy artifact Join Green
Balls
Q47). How will you secure Jenkins
Here are a few steps you should follow to secure
theJenkins: Make sure that global security option is on and Jenkins is
integrated with the company’s user directory with appropriate logindetails.
Make sure that the project matrix is enabled for the finetune access.
Automate the process of setting privileges in Jenkins withcustom
version-controlled scripts. Limit the physical access to
Jenkinsdata/folders. Run the security audits periodically. Jenkins is one of
the popular tools used extensively inDevOps and hands-on training in Jenkins
can make you an expert in the DevOpsdomain.
Q48). What is continuous testing
in DevOps
It is the process of executing automated tests as
part ofsoftware delivery to receive immediate feedback within the latest
build. In this way, each build can be tested continuously allowing the
development team to getfaster feedback and avoid potential problems from
progressing to the next stageof the delivery cycle.
Q49). What is automation testing
in DevOps
It is the process of automating the manual process
fortesting an application under test (AUT). It involves the usage of
differenttesting tools that lets you creating test scripts that can be
executedrepeatedly and does not require any manual intervention.
Q50). Why is automation testing
significant inDevOps
The automation testing is significant for the
followingreasons in DevOps: It supports the execution of repeated test
cases. It helpsin testing a large test matrix quickly. It helps in enabling
the test execution. It encouragesparallel execution. It improves accuracy by
eliminating human intervened errors.It helps in saving the overall time and
investments.
Q51). What is the importance of
continuous testing inDevOps
With continuous testing, all changes to the code
can betested automatically. It avoids the problem created by the big-bang
approach atthe end of the cycle like release delays or quality is sues etc.
In this way,continuous testing assures frequent and quality releases.
Q52). What are the major benefits
of continuous testingtools
The major benefits of continuous testing tools can
be givenbelow. Policy analysis Ris k assessment Requirements traceability
Test optimization Advancedanalytics Service virtualization
Q53). Which testing toolis just
the best as per yourexperience
Selenium testing toolis just the best as per my
experience.Here are a few benefits which makes it suitable for the
workplace. It is an open source free testing toolwith a large userbase and
helping communities. It is compatible with multiple browsers andoperating
systems.
It supports multiple programming
languages with regulardevelopment and dis tributed testing. Q54). What
are the different testing typessupported by the Selenium
These are the Regression Testing and
functionaltesting.
Q55). What is two-factor
authentication in DevOps
Two-factor authentication in DevOps is a security
methodwhere the user is provided with two identification methods from
differentcategories.
Q56). Which type of testing
should be performed to make surethat a new service is ready for
production
It is continuous testing that makes sure that a new
serviceis ready for production.
Q57). What is Puppet
It is a configuration management toolin DevOps that
helpsyou in automating adminis tration tasks.
Q58). What do you understand by
the term CanaryRelease
It is a pattern that reduces the ris k of
introducing a newversion of the software into the production environment. It
is made available ina controlled manner to the subset of users before
releasing to the complete setof users.
Q59). What is the objective of
using PTR in DNS
PTR means pointer record that is required for a
reverse DNSlookup.
Q60). What is Vagrant in DevOps
It is a DevOps toolthat is used for creating and
managingvirtual environments for testing and developing software programs.
DevOps Job Interview Questions and Answers
Q61). What are the prerequis ites
for the successfulimplementation of DevOps
Here are the prerequis ites for the successful
implementationof DevOps: One Version controlsystem Automated testing
Automateddeployment Proper communication among team members
Q62). What are the best practices
to follow for DevOpssuccess
Here are the essential practices to follow for
DevOpssuccess: The speed of delivery time taken for a task to get them
intothe production environment. Focus on different types of defects in
thebuild. Check the average time taken to recover in case offailure.
The total number of reported bugs
by customers impacting thequality of an application. Q63). What is a
SubGit tool
A SubGit toolhelps in migrating from SVN to Git. It
allowsyou to build a writable Git mirror of a remote or local
subversionrepository. Q64). Name a few networks migrating tools. Splunk
Icinga 2 Wireshark NagiosOpenNMS
Q65). How to check either your
video card can run Unity ornot
Here is the command to check either your video card
can rununity or not: /usr/lib/linux/unity_support_test-p It will give you a
depth of unity’s requirements. Ifthey are met, your video card can run
Unity.
Q66). How to enable the start-up
sounds in ubuntu
To enable the start-up sounds in Ubuntu, you should
followthese steps: Click controlgear then click on startupapplications. In
the “startup application preferences” window,click “Add” to add a new entry.
Add the following command in the comment
boxes:/usr/bin/Canberra-gtk-play-id= “desktop-login” – description=“play
login sound” Now, log out from the account once you are done.
Q67). What is the quickest way of
opening an Ubuntu terminalin a particular directory
For this purpose, you can use the custom
keywordshortcuts. To do that, in the command field of a new custom
keyboard,type genome –terminal –working –directory = /path/to/dir.
Q68). How to get the current
color of the screen on theUbuntu desktop
You should open the background image and use a
dropper toolto select the color at a specific point. It will give you the
RGB value for thatcolor at a specific point.
Q69). How to create launchers on
a Ubuntu Desktop
To create a launcher on a Ubuntu desktop, you
should use thefollowing command: ALT+F2 then
type“gnome-desktop-item-edit-create-new~/desktop,” it will launch theold GUI
dialog and create a launcher on your desktop
Q70). What is Memcached in DevOps
It is an open source, high speed, dis tributed
memory object.Its primary objective is enhancing the response time of data
that can otherwis ebe constructed or recovered from another source of
database. It avoids the needfor operating SQL database repetitively to fetch
data for a concurrentrequest. DevOps quiz
Q71). Why Memcached in useful
It speeds up the application processes. It
determines whatto store and share. It reduces the total number of retrieval
requests to thedatabase. It cuts the I/O access from the hard dis k.
Q72). What are the drawbacks of
Memcached
It is not a persis tent data store It is not
adatabase. It is not application-specific. It is not able to cache large
objects.
Q73). What are the features of
Memcached
A few highlighted features of Memcached can be
givenas: CAS Tokens that are used to store the updated objects.Callbacks to
simplify the code. GetDelayed to reduce the response or wait time for
theoutcome. A binary protocolto use with the new client. Igbinary data
option is available to use with the complexdata.
Q74). Can you share a single
instance of Memcached withmultiple instances
Read: Top 20 Git Interview Questions and Answers
2018 Yes,it is possible.
Q75). If you have multiple
Memcached servers and one of theMemcached servers gets failed, then what
will happen
Even if one of the Memcached servers gets failed,
datawon’t get lost, but it can be recovered by configuring it for
multiplenodes.
Q76). How to minimize the
Memcached server outages
If one of the server instances get failed, it will
put ahuge load on the database server. To avoid this , the code should be
written insuch a way that it can minimize the cache stampedes and leave a
minimal impacton the database server. You can bring up an instance of
Memcached on a new machinewith the help of lost IP addresses. You can modify
the Memcached server lis t tominimize the server outages. Set up the timeout
value for Memcached server outages. Ifthe server gets down, it will try to
send a request to the client until thetimeout value is achieved.
Q77). How to update Memcached
when data changes
To update the Memcached in case of data changes,
you can usethese two techniques: Clear the cache proactively Reset the Cache
Q78). What is a Dogpile effect
and how to prevent it
Dogpile effect refers to the event when the cache
expires,and website hits by multiple requests together at the same time. The
semaphorelock can minimize this effect. When the cache expires, the first
processacquires the lock and generates new value as required.
Q79). Explain when Memcached
should not be used
It should not be used as a datastore but a
cacheonly. It should not be taken the only source of information to runyour
apps, but the data should be available through other sources too. It is just
a value store or a key and cannot perform a queryor iterate over contents to
extract the information. It does not offer anysecurity for authentication or
encryption.
Q80). What is the significance of
the blue/green color indeployment pattern
These two colors are used to represent tough
deploymentchallenges for a software project. The live environment is the
Blue environment.When the team prepares the next release of the software, it
conducts the finalstage of testing in the Green environment.
Q81). What is a Container
Containers are lightweight virtualizations that
offeris olation among processes.
Q82). What is post mortem meeting
in DevOps
A post mortem meeting dis cusses what went wrong
and whatsteps to be taken to avoid failures. Q83). Name two tools that can
be used for Docketnetworking. These are Docker Swarm and Kubernetes.
Q84). How to build a small cloud
quickly
Dokku can be a good option to build a small
cloudquickly.
Q85). Name a few common areas
where DevOps is implemented
These are IT, production, operations, marketing,
softwaredevelopment, etc.
Q86). What is pair programming in
DevOps
It is a development practice of extreme
programmingrules.
Q87). What is CBD in DevOps
CBD or component-based development is a unique
style ofapproaching product development.
Q88). What is Resilience Test in
DevOps
It ensures the full recovery of data in case
offailure. Q89). Name a few important DevOps KPis . Three most important
KPis of DevOps can be given as: Meantime to failure recovery Percentage of
faileddeployments Deployment Frequency
Q90). What is the difference
between asset and configurationmanagement
Asset management refers to any system that monitors
andmaintains things of a group or unit. Configuration Management is the
process ofidentifying, controlling, and managing configuration items in
support of changemanagement.
Q91). How does HTTP work
An HTTP protocolworks like any other protocolin
aclient-server architecture. The client initiates a request, and the
serverresponds to it.
Q92). What is Chef
It is a powerful automated toolfor
transforminginfrastructure into code.
Q93). How will you define a
resource in Chef
A resource is a piece of infrastructure and its
desiresstate like packages should be installed, services should be in
running state,the file could be generated, etc.
Q94). How will you define a
recipe in Chef
A recipe is a collection of resources describing
aparticular configuration or policy.
Q95). How is cookbook different
from the recipe inChef
The answer is pretty direct. A recipe is a
collection ofresources, and a Cookbook is a collection of recipes and
otherinformation.
Q96). What is an Ansible Module
Modules are considered as a unit of work in
Ansible. Eachmodule is standalone, and it can be written in common
scriptinglanguages.
Q97). What are playbooks in
Ansible
Playbooks are Ansible’s orchestration,
configuration,and deployment languages. They are written in human-readable
basic textlanguage.
Q98). How can you check the
complete lis t of Ansiblevariables
You can use this command to check the complete lis
t ofAnsible variables. Ansible –m setup hostname
Q99). What is Nagios
It is a DevOps toolfor continuous monitoring of
systems,business processes, or application services, etc.
Q100). What are plugins in DevOps
Plugins are scripts that are run from a command
line tocheck the status of Host or Service.
Question:What Are Benefits
OfDevOps
DevOps is gaining more popularity day by day. Here
are somebenefits of implementing DevOps Practice. Release Velocity:DevOps
enable organizations to achieve a great release velocity. We canrelease code
to production more often and without any hectic problems. Development
Cycle:DevOps shortens the development cycle from initial design
toproduction. Full Automation:DevOps helps to achieve full automation from
testing, to build, releaseand deployment. Deployment Rollback:In DevOps, we
plan for any failure in deployment rollback due to a bugin code or is sue in
production. This gives confidence in releasing featurewithout worrying about
downtime for rollback. Defect Detection:With DevOps approach, we can catch
defects much earlier than releasingto production. It improves the quality of
the software. Collaboration:WithDevOps, collaboration between development
and operations professionalsincreases. Performance-oriented:With DevOps,
organization follows performance-oriented culturein Feb-71 which teams
become more productive and moreinnovative.
Question: What is The Typical
DevOps workflow
The typical DevOps workflow is as follows:
Atlassian Jira for writingrequirements and tracking tasks. Based on the Jira
tasks,developers checking code into GIT version controlsystem. The code
checked into GIT is built by using Apache Maven. The build process is
automatedwith Jenkins. During the build process,automated tests run to
validate the code checked in by adeveloper. Code built on Jenkins is sentto
organization’s Artifactory. Jenkins automatically picksthe libraries from
Artifactory and deploys it to Production. During Production
deployment,Docker images are used to deploy same code on multiplehosts. Once
a code is deployed toProduction, we use monitoring tools like ngios are used
tocheck the health of production servers. Splunk based alerts inform
theadmins of any is sues or exceptions in production.
Question: DevOps Vs Agile
Agile is a set of values and principles about how
to developsoftware in a systematic way. Where as DevOPs is a way to quickly,
easily and repeatablymove that software into production infrastructure, in a
safe and simpleway. In oder to achieve that we use a set of DevOps tools
andtechniques.
Question: What is The Most
ImportantThing DevOps Helps Us To Achieve
Most important aspect of DevOps is to get the
changes intoproduction as quickly as possible while minimizing ris ks in
software qualityassurance and compliance. This is the primary objective of
DevOps. Question: What Are Some DevOps tools. Here is a lis t of some most
important DevOps tools Git Jenkins, Bamboo Selenium Mar-71 Puppet, BitBucket
Chef Ansible, Artifactory Nagios Docker Monit ELK –Elasticsearch,Logstash,
Kibana Collectd/Collect
Question:How To DeploySoftware
Code is deployed by adopting continuous delivery
bestpractices. Which means that checked in code is built automatically and
thenartifacts are publis hed to repository servers. On the application
severs there are deployment triggersusually timed by using cron jobs. All
the artifacts are then downloaded anddeployed automatically. Gradle DevOps
Interview Questions
Question:What is Gradle
Apr-71 Gradle is an open-source build automation
system that buildsupon the concepts of Apache Ant and Apache Maven. Gradle
has a properprogramming language instead of XML configuration file and the
language is called ‘Groovy’. Gradle uses a directed acyclic graph("DAG") to
determine the order in which tasks can be run. Gradle was designed for
multi-project builds, which can growto be quite large. It supports
incremental builds by intelligently determiningwhich parts of the build tree
are up to date, any task dependent only on thoseparts does not need to be
re-executed.
Question: What Are Advantages of
Gradle
Gradle provides many advantages and here is a lis t
Declarative Builds:Probably one of the biggest advantage of Gradleis Groovy
language. Gradle provides declarative languageelements. Which providea
build-by- convention support for Java, Groovy, Web andScala. Structured
Build:Gradle allows developers to apply common designprinciples to their
build. It provides a perfect structurefor build, so that well-structured and
easily maintained, comprehensible buildstructures can be built. Deep
API:Using this API, developers can monitor andcustomize its configuration
and executionbehaviors. Scalability:Gradle can easily increase productivity,
fromsimple and single project builds to huge enterpris emulti-project
builds.Multi-project builds:Gradle supports multi-project buildsand also
partial builds. Build management:Gradle supports different strategies to
manage project dependencies. First buildintegration tool − Gradle
completelysupports ANT tasks, Maven and lvy repositoryinfrastructure for
publis hing and retrieving dependencies. It also provides aconverter for
turning a Maven pom.xml to Gradle script. Ease of migration:Gradle can
easily adapt to any projectstructure. Gradle Wrapper:Gradle Wrapper allows
developers to executeGradle builds on machines where Gradle is not
installed.This is useful for continuous integration of servers. Free open
source− Gradle is an open source project, andlicensed under the Apache
Software License (ASL). Groovy:Gradle's build scripts are written inGroovy,
not XML. But unlike other approaches this is notfor simply exposing the raw
scripting power of a dynamic language. The wholedesign of Gradle is oriented
towards being used as a language, not as a rigidframework.
Question: Why Gradle is Preferred
Over Maven or Ant
May-71 There is n't a great support for
multi-project builds inAnt and Maven. Developers end up doing a lot of
coding to support multi-projectbuilds. Also having some build-by-convention
is nice and makes buildscripts more concis e. With Maven, it takes build by
convention too far, andcustomizing your build process becomes a hack. Maven
also promotes every project publis hing an artifact.Maven does not support
subprojects to be built and versioned together. But with Gradle developers
can have the flexibility of Antand build by convention of Maven. Groovy is
easier and clean to code than XML. In Gradle,developers can define
dependencies between projects on the local file systemwithout the need to
publis h artifacts to repository. Question: Gradle Vs Maven The following is
a summary of the major differences betweenGradle and Apache Maven:
Flexibility:Googlechose Gradle as the official build toolfor Android; not
because build scriptsare code, but because Gradle is modeled in a way that
is extensible in the mostfundamental ways. Both Gradle and Maven provide
convention over configuration.However, Maven provides a very rigid model
that makes customization tedious andsometimes impossible. While this can
make it easier to understand any given Mavenbuild, it also makes it
unsuitable for many automation problems. Gradle, on theother hand, is built
with an empowered and responsible user in mind. Performance Both Gradle and
Maven employ some form of parallel projectbuilding and parallel dependency
resolution. The biggest differences areGradle's mechanis ms for work
avoidance and incrementally. Followingfeatures make Gradle much faster than
Maven: Incrementally:Gradle avoids work bytracking input and output of tasks
and only running whatis necessary. BuildCache:Reuses the build outputs of
any otherGradle build with the same inputs. GradleDaemon:A long-lived
process that keeps buildinformation "hot" in memory. User Experience Maven's
has a very good support for various IDE's.Gradle's IDE support continues to
improve quickly but is not great as ofMaven. Jun-71 Although IDEs are
important, a large number of users preferto execute build operations through
a command-line interface. Gradle provides amodern CLI that has dis
coverability features like `gradle tasks`, as well asimproved logging and
command-line completion. Dependency Management Both build systems provide
built-in capability to resolvedependencies from configurable repositories.
Both are able to cache dependencieslocally and download them in parallel. As
a library consumer, Maven allows one to override adependency, but only by
version. Gradle provides customizable dependencyselection and substitution
rules that can be declared once and handle unwanteddependencies
project-wide. This substitution mechanis m enables Gradle to buildmultiple
source projects together to create composite builds. Maven has few, built-in
dependency scopes, which forcesawkward module architectures in common
scenarios like using test fixtures orcode generation. There is no separation
between unit and integration tests, forexample. Gradle allows custom
dependency scopes, which providesbetter-modeled and faster builds.
Question: What are Gradle Build
Scripts
Gradle builds a script file for handling projects
and tasks.Every Gradle build represents one or more projects. A project
represents a library JAR or a webapplication.
Question: What is Gradle Wrapper
The wrapper is a batch script on Windows, and a
shell scriptfor other operating systems. Gradle Wrapper is the preferred way
of starting aGradle build. When a Gradle build is started via the wrapper,
Gradle willautomatically download and run the build.
Question: What is Gradle Build
Script File Name
This type of name is written in the format that is
build.gradle. It generally configures the Gradle scripting language.
Question: How To Add Dependencies
In Gradle
In order to make sure that dependency for your
project is added, you need to mention the Jul-71 configuration dependency
like compiling the blockdependencies of the build.gradle file.
Question: What is Dependency
Configuration
Dependency configuration compris es of the
externaldependency, which you need to install well and make sure the
downloading is donefrom the web. There are some key features of this
configuration whichare: Compilation:The projectwhich you would be starting
and working on the first needs to be wellcompiled and ensure that it is
maintained in the good condition. Runtime:It is the desiredtime which is
required to get the work dependency in the form ofcollection. Test
Compile:Thedependencies check source requires the collection to be made for
running theproject. Test runtime:This is thefinal process which needs the
checking to be done for running the test thatis in a default manner
considered to be the mode of runtime
Question: What is Gradle Daemon
A daemon is a computer program that runs as a
backgroundprocess, rather than being under the direct controlof an
interactiveuser. Gradle runs on the Java Virtual Machine (JVM) and
usesseveral supporting libraries that require a non-trivial
initializationtime. As a result, it can sometimes seem a little slow to
start.The solution to this problem is the Gradle Daemon : a long-lived
background processthat executes your builds much more quickly than would
otherwis e be thecase. We accomplis h this by avoiding the expensive
bootstrappingprocess as well as leveraging caching, by keeping data about
your project inmemory. Running Gradle builds with the Daemon is no different
thanwithout
Question: What is Dependency
Management in Gradle
Software projects rarely work in is olation. In
most cases, aproject relies on reusable functionality in the form of
libraries or is brokenup into individual components to compose a modularized
system. Dependency management is a technique for declaring,resolving and
using dependencies required by the project in an automatedfashion. Aug-71
Gradle has built-in support for dependency management andlives up the task
of fulfilling typical scenarios encountered in modern softwareprojects.
Question: What Are Benefits Of Daemon in Gradle 3.0 Here are some of the
benefits of Gradle daemon It has good UX It is very powerful It is aware of
the resource It is well integrated with the Gradle Build scans It has been
default enabled
Question: What is Gradle
Multi-Project Build
Multi-project builds helps with modularization. It
allows aperson to concentrate on one area of work in a larger project, while
Gradletakes care of dependencies from other parts of the project A
multi-project build in Gradle consis ts of one rootproject, and one or more
subprojects that may also have subprojects. While each subproject could
configure itself in completeis olation of the other subprojects, it is
common that subprojects share commontraits. It is then usually preferable to
share configurations amongprojects, so the same configuration affects
several subprojects.
Question: What is Gradle Build
Task
Gradle Build Tasks is made up of one or more
projects and aproject represents what is been done with Gradle. Some key of
features of Gradle Build Tasks are: Task has life cycled methods [do first,
do last] Build Scripts are code Default tasks like run, clean etc Task
dependencies can be defined using properties likedependsOn
Question: What is Gradle Build
Life Cycle
Sep-71 Gradle Build life cycle consis ts of
following threesteps -Initialization phase:In this phase the project layer
or objects are organized -Configuration phase:In this phase all the tasks
are available for the current build and adependency graph is created
-Execution phase:Inthis phase tasks are executed.
Question: What is Gradle Java
Plugin
The Java plugin adds Java compilation along with
testing andbundling capabilities to the project. It is introduced in the way
of a SourceSetwhich act as a group of source files complied and executed
together.
Question: What is Dependency
Configuration
A set of dependencies is termed as dependency
configuration,which contains some external dependencies for download and
installation. Here are some key features of dependency configurationare:
Compile: The project must be able to compile together Runtime: It is the
required time needed to get the dependency work inthe collection. Test
Compile: The check source of the dependencies is to be collected inorder to
run the project. Test Runtime: The final procedure is to check and run the
test which is bydefault act as a runtime mode. Groovy DevOps Interview
Questions Oct-71
Question: What is Groovy
Apache Groovy is a object-oriented programming
language forthe Java platform. It is both a static and dynamic language with
featuressimilar to those of Python, Ruby, Perl, and Smalltalk. It can be
used as both a programming language and ascripting language for the Java
Platform, is compiled to Java virtual machine(JVM) bytecode, and
interoperates seamlessly with other Java code andlibraries. Groovy uses a
curly-bracket syntax similar to Java. Groovysupports closures, multiline
strings, and expressions embedded instrings. And much of Groovy's power lies
in itsASTtransformations, triggered through annotations.
Question: Why Groovy is Gaining
Popularity
Here are few reasons for popularity of Groovy
Familiar OOP languagesyntax. Extensive stock of variousJava libraries Nov-71
Increased expressivity (typeless to do more) Dynamic typing (lets you
codemore quickly, at least initially) Closures Native
associativearray/key-value mapping support (you can create an associative
array literal) String interpolation (cleanercreation of strings dis playing
values) Regex's being first classcitizens Question: What is Meant By Thin
Documentation InGroovy Groovy is documented very badly. In fact the
coredocumentation of Groovy is limitedand there is no information regarding
thecomplex and run-time errors that happen. Developers are largely on there
own and they normally haveto figure out the explanations about internal
workings by themselves.
Question: How To Run Shell
Commands in Groovy
Groovy adds the execute method to String to
makeexecuting shells fairly easy println "ls".execute().text
Question: In How Many Platforms
you can use Groovy
These are the infrastructure components where we
can usegroovy: -Application Servers -Servlet Containers -Databases with JDBC
drivers -All other Java-based platforms
Question: Can Groovy Integrate
With Non Java BasedLanguages
image It is possible but in this case the features
are limited.Groovy cannot be made to handle all the tasks in a manner it has
to.
Question: What are
Pre-Requirements For Groovy
Dec-71 image Installing and using Groovy is easy.
Groovy does not havecomplex system requirements. It is OS independent.
Groovy can perform optimally in every situation.There aremany Java based
components in Groovy,which make it even more easier to work withJava
applications.
Questions: What is Closure In
Groovy
A closure in Groovy is an open, anonymous, block of
codethat can take arguments, return a value and be assigned to a variable. A
closuremay reference variables declared in its surrounding scope. In
opposition to theformal definition of a closure, Closure in the Groovy
language can also contain free variables which aredefined outside of its
surrounding scope. A closure definition follows this syntax: {
[closureParameters -> ] statements } Where [closureParameters->] is an
optional comma-delimited lis t of parameters, andstatements are 0 or more
Groovy statements. The parameters look similar to amethod parameter lis t,
and these parameters may be typed or untyped. When a parameter lis t is
specified, the -> character is required and serves toseparate the arguments
from the closure body. The statements portion consis ts of 0, 1, ormany
Groovy statements.
Question: What is ExpandoMeta
Class In Groovy
Through this class programmers can add
properties,constructors, methods and operations in the task. It is a
powerful optionavailable in the Groovy. By default this class cannot be
inherited and users need tocall explicitly. The command for this is
“ExpandoMetaClass.enableGlobally()”.
Question: What Are Limitations Of
Groovy
Groovy has some limitations. They are described
below It can be slower than theother object-oriented programming languages.
It might need memory more thanthat required by other languages. The start-up
time of groovyrequires improvement. It is not that frequent. For using
groovy, you need tohave enough knowledge of Java. Knowledge of Java is
important because half of groovy is based on Java. 13/71 It might take you
some time toget used to the usual syntax and default typing. It consis ts of
thindocumentation. Question: How To Write HelloWorld Program In Groovy The
following is a basic Hello World program written inGroovy: class Test {
static void main(String[] args) { println('Hello World'); } }
Question: How To Declare String
In Groovy
In Groovy, the following steps are needed to
declare astring. The string is closed withsingle and double qotes. It
contains Groovy Expressionsnoted in ${} Square bracket syntax may beapplied
like charAt(i)
Question: Differences Between
Java And Groovy
Groovy tries to be as natural as possible for
Javadevelopers. Here are all the major differences between Java and Groovy.
-Default imports In Groovy all these packages and classes are imported
bydefault, i.e. Developers do not have to use an explicit import statement
to use them: java.io.* java.lang.* java.math.BigDecimal java.math.BigInteger
java.net.* java.util.* groovy.lang.* groovy.util.* -Multi-methods 14/71 In
Groovy, the methods which will be invoked are chosen atruntime. This is
called runtime dis patch or multi-methods. It means that themethod will be
chosen based on the types of the arguments at runtime. In Java,this is the
opposite: methods are chosen at compile time, based on the declaredtypes.
-Array initializers In Groovy, the { … } block is reserved for closures.
That means that you cannotcreate array literals with this syntax: int[]
arraySyntex = { 6, 3, 1} You actually have to use: int[] arraySyntex =
[1,2,3] -ARM blocks ARM (Automatic Resource Management) block from Java 7
arenot supported in Groovy. Instead, Groovy provides various methods relying
onclosures, which have the same effect while being more idiomatic. -GStrings
As double-quoted string literals are interpreted as GString values, Groovy
may fail withcompile error or produce subtly different code if a class with
String literal containing a dollar character is compiled with Groovy and
Java compiler. While typically, Groovy will auto-cast between GString and
String if an API declares the type of a parameter, beware of JavaAPis that
accept an Object parameterand then check the actual type. -String and
Character literals Singly-quoted literals in Groovy are used for String ,
and double-quoted result in String or GString , depending whether there is
interpolation in the literal. image image assert 'c'.getClass()==String
assert"c".getClass()==String assert "c${1}".getClass() in GString Groovy
will automatically cast a single-character String to char only when
assigning to a variable of type char . When calling methods with arguments
oftype char we need to either castexplicitly or make sure the value has been
cast in advance. char a='a' assert Character.digit(a, 16)==10 : 'But Groovy
doesboxing' assert Character.digit((char) 'a', 16)==10 try { assert
Character.digit('a', 16)==10 assert false:'Need explicit cast' 15/71 }
catch(Mis singMethodException e) { } Groovy supports two styles of casting
and in the case ofcasting to char there are subtledifferences when casting a
multi-char strings. The Groovy style cast is morelenient and will take the
first character, while the C-style cast will fail withexception. // for
single char strings, both arethe same assert ((char) "c").class==Character
assert ("c" as char).class==Character // for multi char strings they arenot
try { ((char) 'cx') == 'c' assert false: 'will fail - not castable' }
catch(GroovyCastException e) { } assert ('cx' as char) == 'c'
assert'cx'.asType(char) == 'c' -Behaviour of In Java == meansequality of
primitive types or identity for objects. In Groovy == translates to
a.compareTo(b)==0 , if they are Comparable , and a.equals(b) otherwis e. To
check for identity, there is is . E.g. a.is (b) .image
Question: How To Test Groovy
Application
The Groovy programming language comes with great
support forwriting tests. In addition to the language features and test
integration withstate-of-the-art testing libraries and frameworks. The
Groovy ecosystem has born a rich set of testinglibraries and frameworks.
Groovy Provides following testing capabilities Junit Integrations Spock for
specifications Geb for Functional Test Groovy also has excellent built-in
support for a range ofmocking and stubbing alternatives. When using Java,
dynamic mocking frameworksare very popular. A key reason for this is that it
is hard work creatingcustom hand-crafted mocks using Java. Such frameworks
can be used easily with Groovy.
Question: What Are Power
Assertions In Groovy
16/71 Writing tests means formulating assumptions
by usingassertions. In Java this can be done by using the assert keyword.
But Groovy comes with a powerful variant of assert also known as power
assertion statement . Groovy’s power assert differs from the Java version in
its output given the booleanexpression validates to false : def x = 1 assert
x == 2 // Output: // // Assertion failed: // assert x == 2 // | | // 1 false
This section shows the std-err output The java.lang.AssertionError that is
thrown whenever the assertion can not be validatedsuccessfully, contains an
extended version of the original exception message.The power assertion
output shows evaluation results from the outer to the innerexpression. The
power assertion statements true power unleashes in complexBoolean
statements, or statements with collections or other toString -enabled
classes: def x = [1,2,3,4,5] assert (x << 6)==[6,7,8,9,10] // // // Output:
Assertion failed: // assert (x << 6)==[6,7,8,9,10] // | | | // | | false
// | [1, 2, 3, 4, 5, 6] // [1, 2, 3, 4, 5, 6]
Question: Can We Use Design
Patterns In Groovy
Design patterns can also be used with Groovy.
Here areimportant points Some patterns carry overdirectly (and can make
use of normal Groovy syntax improvements for greater readability) Some
patterns are no longerrequired because they are built right into the
language orbecause Groovy supports a better way of achieving the intent
of thepattern some patterns that have to beexpressed at the design level
in other languages can be implemented directly inGroovy (due to the way
Groovy can blur the dis tinction between design andimplementation)
Question: How To Parse And
Produce JSON Object InGroovy
17/71 Groovy comes with integrated support for
converting betweenGroovy objects and JSON. The classes dedicated to JSON
serialis ation and parsingare found in the groovy.json a class that
parses JSON text or reader content into Groovydata structures (objects)
such as maps, lis ts and primitive types like Integer , Double , Boolean
and String . The class comes with a bunch of overloaded parse methods
plus some special methods such as parseText , parseFile and others
Question: What is Difference
Between XmlParser AndXmlSluper
XmlParser and XmlSluper are used for parsing
XML withGroovy. Both have the same approach to parse an xml. Both come
with a bunch of overloaded parse methods plus somespecial methods such
as parseText ,parseFile and others. XmlSlurper def text = '''
Groovy
''' def lis t = new XmlSlurper().parseText(text) assert lis t
instanceofgroovy.util.slurpersupport.GPathResult assert lis
t.technology.name =='Groovy' Parsing the XML an returning the root node
as aGPathResult Checking we’re using a GPathResult Traversing the tree
in a GPath style XmlParser 18/71 def text = '''
Groovy
''' def lis t = new XmlParser().parseText(text) assert lis t
instanceof groovy.util.Node assertlis t.technology.name.text() ==
'Groovy' Parsing the XML an returning the root node as a Node Checking
we’re using a Node Traversing the tree in a GPath style Let’s see the
similarities betweenXMLParser andXMLSlurperfirst: Both are based on SAX
so they both are low memory footprint image Both canupdate/transform the
XML But they have key differences: XmlSlurper evaluates the
structurelazily. So if you update the xml you’ll have to evaluate the
whole treeagain. XmlSlurper returns GPathResult instances when parsing
XML XmlParser returns Node objects when parsing XML
When to use one or the
another
If you want to transform anexis ting document
to another then be the choice If you want to update and readat the same
time then XmlParser is the choice. Maven DevOps Interview Questions
19/71 image
Question: What is Maven
Mavenis a buildautomation toolused primarily
for Java projects. Maven addresses twoaspects of building software:
First:It describeshow software is built Second:It describesits
dependencies. Unlike earlier tools like Apache Ant, it uses
conventionsfor the build procedure, and only exceptions need to be
written down. An XML file describes the software project being built,
itsdependencies on other external modules and components, the build
order,directories, and required plug-ins. It comes with pre-defined
targets for performing certainwell-defined tasks such as compilation of
code and its packaging. Maven dynamically downloads Java libraries and
Mavenplug-ins from one or more repositories such as the Maven 2 Central
Repository,and stores them in a local cache. This local cache of
downloaded artifacts can also be updatedwith artifacts created by local
projects. Public repositories can also beupdated. 20/71
Question: What Are Benefits
Of Maven
One of the biggest benefit ofMaven is that its
design regards all projects as having acertain structure and a set of
supported task work-flows. Maven has quick project setup,no complicated
build.xml files, just a POM and go All developers in aproject use the
same jar dependencies due to centralized POM. In Maven getting a
numberof reports and metrics for a project "for free" It reduces the
size of sourcedis tributions, because jars can be pulled from a
centrallocation Maven lets developers get yourpackage dependencies
easily With Maven there is no need toadd jar files manually to the class
path
Question: What Are Build Life
cycles In Maven
Build lifecycle is a lis t of named phases that
can be usedto give order to goal execution. One of Maven's standard life
cycles is the default lifecycle , whichincludes the following phases, in
this order validate generate-sources process-sources generate-resources
process-resources compile process-test-sources process-test-resources
test-compile test package install deploy
Question: What is Meant By
Build Tool
Build tools are programs that automate the
creation ofexecutable applications from source code. Building
incorporates compiling,linking and packaging the code into a usable or
executable form. In small projects, developers will often manually
invoke thebuild process. This is not practical for larger projects.
Where it is very hard to keep track of what needs to bebuilt, in what
sequence and what dependencies there are in the building process.Using
an automation toollike Maven, Gradle or ANT allows the build process
tobe more consis tent. 21/71
Question: What is Dependency
Management Mechanis m InGradle
image Maven's dependency-handling mechanis m is
organizedaround a coordinate system identifying individual artifacts
such as softwarelibraries or modules. For example if a project needs
Hibernate library. Ithas to simply declare Hibernate's project
coordinates in its POM. Maven will automatically download the dependency
and thedependencies that Hibernate itself needs and store them in the
user's localrepository. Maven 2 Central Repository is used by default
tosearch for libraries, but developers can configure the custom
repositories to beused (e.g., company-private repositories) within the
POM.
Question: What is Central
Repository Search Engine
The Central Repository Search Engine, can be
used to findout coordinates for different open-source libraries and
frameworks.
Question: What are Plugins In
Maven
Most of Maven's functionality is in plugins.
Aplugin provides a set of goals that can be executed using the
followingsyntax: mvn [plugin-name]:[goal-name] For example, a Java
project can be compiled with thecompiler-plugin's compile-goal by
running mvncompiler:compile . There are Maven plugins for
building,testing, source control management, running a web server,
generating Eclipseproject files, and much more. image Plugins are
introduced and configured in a
-section of a pom.xml file.
Some basic plugins are included in every project by default, andthey
have sensible default settings.
Questions: What is Difference
Between Maven And ANT
Ant Maven Ant is a toolbox. Maven is a
framework. There is no life cycle. There is life cycle. 22/71 Ant
doesn't have formal Maven has a convention to place source code,compiled
code conventions. etc. Ant is procedural. Maven is declarative. The ant
scripts are not reusable. The maven plugins are reusable.
Question: What is POM In
Maven
A Project Object Model (POM) provides all the
configurationfor a single project. General configuration covers the
project's name, itsowner and its dependencies on other projects. One can
also configure individual phases of the buildprocess, which are
implemented as plugins. For example, one can configure the
compiler-plugin to useJava version 1.5 for compilation, or specify
packaging the project even if someunit tests fail. Larger projects
should be divided into several modules, orsub-projects, each with its
own POM. One can then write a root POM through whichone can compile all
the modules with a single command. POMs can also inheritconfiguration
from other POMs. All POMs inherit from the Super POM by default.The
Super POM provides default configuration, such as default
sourcedirectories, default plugins, and so on.
Question: What is Maven
Archetype
Archetype is a Maven project templating
toolkit. Anarchetype is defined as an original pattern or model from
which all other thingsof the same kind are made.
Question: What is Maven
Artifact
In Maven artifact is simply a file or JAR that
is deployedto a Maven repository. An artifact has -Group ID -Artifact ID
-Version string. The three together uniquely identify theartifact. All
the project dependencies are specified as artifacts.
Question: What is Goal In
Maven
In Maven a goal represents a specific task
which contributesto the building and managing 23/71 of a project. It may
be bound to 1 or many build phases. A goal not boundto any build phase
could be executed outside of the build lifecycle by itsdirect
invocation.
Question: What is Build
Profile
In Maven a build profile is a set of
configurations. This set is used to define or override default behaviour
of Maven build. Build profile helps the developers to customize the
buildprocess for different environments. For example you can set
profiles for Test,UAT, Pre-prod and Prod environments each with its own
configurations etc.
Question: What Are Build
Phases In Maven
There are 6 build phases. -Validate -Compile
-Test -Package-Install -Deploy
Question: What is Target,
Source & Test Folders InMavn
Target:folder holdsthe compiled unit of code as
part of the build process. Source:folder usually holds javasource
codes.Test: directory contains all the unit testing codes.
Question: What is Difference
Between Compile &Install
Compile:is used tocompile the source code of
the project Install: installs the package into the local repository,for
use as a dependency in other projects locally.Design patterns can also
beused with Groovy. Here are important points
Question: How To Activate
Maven Build Profile
A Maven Build Profile can be activated in
followingways Using command line consoleinput. By using Mavensettings.
Based on environment variables(User/System variables). Linux DevOps
Interview Questions 24/71 image
Question: What is Linux
Linux is the best-known and most-used open
sourceoperating system. As an operating system, Linux is a software that
sitsunderneath all of the other software on a computer, receiving
requests from those programs and relaying theserequests to the
computer’s hardware. In many ways, Linux is similar to other operating
systemssuch as Windows, OS X, or iOS But Linux also is different from
other operating systems inmany important ways. First, and perhaps most
importantly, Linux is open sourcesoftware. The code used to create Linux
is free and available to the public toview, edit, and—for users with the
appropriate skills—to contributeto. Linux operating system is consis t
of 3 components which areas below: Kernel:Linux is a monolithic kernel
that is free andopen source software that is responsible for
managinghardware resources for the users. System Library:System Library
plays a vital role becauseapplication programs access Kernels feature
using systemlibrary. System Utility:System Utility performs specific and
individuallevel tasks. 25/71
Question: What is Difference
Between Linux &Unix
Unix and Linux are similar in many ways, and in
fact, Linuxwas originally created to be similar to Unix. Both have
similar tools for interfacing with the systems,programming tools,
filesystem layouts, and other key components. However, Unix is not free.
Over the years, a number ofdifferent operating systems have been created
that attempted to be“unix-like” or “unix-compatible,” but Linux has been
themost successful, far surpassing its predecessors in popularity.
Question: What is BASH
BASH stands forBourne AgainShell. BASH is the
UNIX shell for the GNUoperating system. So, BASH is the command language
interpreter that helps you toenter your input, and thus you can retrieve
information. In a straightforward language, BASH is a program that
willunderstand the data entered by the user and execute the command and
givesoutput.
Question: What is CronTab
The crontab (short for "cron table") is a lis t
ofcommands that are scheduled to run at regular time intervals on
computer system.Thecrontabcommandopens the crontab for editing, and lets
you add, remove, or modify scheduledtasks. The daemon which reads the
crontab and executes the commandsat the right time is called cron. It's
named after Kronos, the Greekgod of time. Command syntax crontab [-u
user ] file crontab [-u user ] [-l | -r | -e] [-i] [-s]
Question: What is Daemon In
Linux
Adaemonis a type of program on Linux operating
systems that runs unobtrusivelyin the background, rather than under the
direct controlof a user, waiting to beactivated by the occurrence of a
specific event or condition 26/71 Unix-like systems typically run
numerous daemons, mainly toaccommodate requests for services from other
computers on a network, but also torespond to other programs and to
hardware activity. Examples of actions or conditions that can trigger
daemonsinto activity are a specific time or date, passage of a specified
time interval,a file landing in a particular directory, receipt of an
e-mail or a Web requestmade through a particular communication line. It
is not necessary that the perpetrator of the action orcondition be aware
that a daemon is lis tening , although programs frequentlywill perform
an action only because they are aware that they will implicitlyarouse a
daemon.
Question: What is Process In
Linux
Daemons are usually instantiated as processes .
A process is an executing (i.e., running)instance of a program.
Processes are managed by the kernel (i.e., the core of theoperating
system), which assigns each a unique process identification number
(PID). There are three basic types of processes inLinux:
-Interactive:Interactive processes are run interactively by a user at
the command line -Batch:Batchprocesses are submitted from a queue of
processes and are not associated withthe command line; they are well
suited for performing recurring tasks whensystem usage is otherwis e
low. -Daemon:Daemons arerecognized by the system as any processes whose
parent process has a PID ofone
Question: What is CLI In
Linux
CLI (Command Line Interface) is a type of
human-computer interface that reliessolely on textual input and output.
That is , the entire dis play screen, or the currently activeportion of
it, shows only characters (and no images), and input is usuallyperformed
entirely with a keyboard.
Questions: What is Linux
Kernel
A kernel is the lowest level of easily
replaceable softwarethat interfaces with the hardware in your computer.
It is responsible for interfacing all of your applicationsthat are
running in “user mode” down 27/71 to the physical hardware, and allowing
processes, known asservers, to get information from each other using
inter-process communication(IPC). There are three types of Kernals
Microkernel:Amicrokernel takes the approach of only managing what it has
to: CPU, memory, andIPC. Pretty much everything else in a computer can
be seen as an accessory andcan be handled in user mode. Monolithic
Kernel:Monolithic kernels are the opposite of microkernels because
theyencompass not only the CPU, memory, and IPC, but they also include
things likedevice drivers, file system management, and system server
calls Hybrid Kernel:Hybridkernels have the ability to pick and choose
what they want to run in user modeand what they want to run in supervis
or mode. Because the Linux kernel is monolithic, it has the largest
footprint and the most complexity over the othertypes of kernels. This
was a design feature which was under quite a bit ofdebate in the early
days of Linux and still carries some of the same designflaws that
monolithic kernels are inherent to have.
Question: What is Partial
Backup In Linux
Partial backup refers to selecting only a
portion of filehierarchy or a single partition to back up.
Question: What is Root
Account
The root account a system adminis trator
account. It providesyou full access and controlof the system. Admin can
create and maintain user accounts, assigndifferent permis sion for each
account etc
Question: What is Difference
Between Cron andAnacron
One of the main difference between cron and
anacron jobs is that cron works on the system that are running
continuously. While anacron is used for the systems that are not
runningcontinuously. Other difference between the two is cron jobs can
run everyminute, but anacron jobs can be run only once a day. Any normal
user can do the scheduling of cron jobs, but thescheduling of anacron
jobs can be done by the superuser only. 28/71 Cron should be used when
you need to execute the job at aspecific time as per the given time in
cron, but anacron should be used inwhen there is no any restriction for
the timing and can be executed at anytime. If we think about which one
is ideal for servers or desktops,then cron should be used for servers
while anacron should be used fordesktops or laptops.
Question: What is Linux
Loader
Linux Loader is a boot loader for Linux
operating system. Itloads Linux into into the main memory so that it can
begin itsoperations.
Question: What is Swap Space
Swap space is the amount of physical memory
that is allocated for use by Linux to hold some concurrent running
programstemporarily. This condition usually occurs when Ram does not
have enoughmemory to support all concurrent running programs. This
memory management involves the swapping of memory toand from physical
storage.
Question: What Are Linux Dis
tributors
There are around six hundred Linux dis
tributors. Let us seesome of the important ones UBuntu: It is a well
known Linux Dis tributionwith a lot of pre-installed apps and easy to
userepositories libraries. It is very easy to use and works like MAC
operatingsystem. Linux Mint: It uses cinnamon and mate desktop. Itworks
on windows and should be used by newcomers. Debian: It is the most
stable, quicker anduser-friendly Linux Dis tributors. Fedora: It is less
stable but provides thelatest version of the software. It has GNOME3
desktopenvironment by default. Red HatEnterpris e: It is to be
usedcommercially and to be well tested before release. Itusually
provides the stable platform for a long time. Arch Linux: Every package
is to be installed by youand is not suitable for the beginners.
Question: Why Do Developers
Use MD5
MD5 is an encryption method so it is used to
encrypt thepasswords before saving.
Question: What Are File
Permis sions In Linux
29/71 image There are 3 types of permis sions
in Linux Read:User can read the file and lis t thedirectory. Write:User
can write new files in the directory. Execute:User can access and run
the file in adirectory.
Question: Memory Management
In Linux
It is always required to keep a check on the
memory usage inorder to find out whether the user is able to access the
server or the resourcesare adequate. There are roughly 5 methods that
determine the total memory usedby the Linux. This is explained as below
Freecommand : This is the most simple and easy to use thecommand to
check memory usage. For example: ‘$ free –m’,the option ‘m’ dis plays
all the data in MBs. /proc/meminfo:The next way to determine the memory
usage is toread /proc/meminfo file. For example: ‘$ cat/proc/meminfo’
Vmstat : This command basically lays out the memory usagestatis tics.
For example: ‘$ vmstat –s’ Topcommand : This command determines the
total memory usage aswell as also monitors the RAM usage. Htop : This
command also dis plays the memory usage alongwith other details.
Question: Granting Permis
sions In Linux
System adminis trator or the owner of the file
can grantpermis sions using the ‘chmod’ command. Following symbols are
usedwhile writing permis sions chmod +x
Question: What Are Directory
Commands In Linux
Here are few important directory commands in
Linux pwd: It is a built-in command which standsfor‘print
workingdirectory’. It dis plays the current working location, working
path starting with / anddirectory of the user. Basically, it dis plays
the full path to the directory youare currently in. is : This command
lis t out all thefiles in the directed folder. cd: This stands for
‘changedirectory’. This command is used to change to the 30/71 directory
you want to work from the present directory. Wejust need to type cd
followed by the directory name to access that particulardirectory.
mkdir: This command is used to create anentirely new directory. rmdir:
This command is used to remove adirectory from the system.
Question: What is Shell
Script In Linux
In the simplest terms, a shell script is a file
containing aseries of commands. The shell reads this file and carries
out the commands asthough they have been entered directly on the command
line. The shell is somewhat unique, in that it is both a powerfulcommand
line interface to the system and a scripting languageinterpreter. As we
will see, most of the things that can be done on thecommand line can be
done in scripts, and most of the things that can be done inscripts can
be done on the command line. We have covered many shell features, but we
have focused onthose features most often used directly on the command
line. The shell also provides a set of features usually (but notalways)
used when writing programs.
Question: Which Tools Are
Used For Reporting Statis tics InLinux
Some of the popular and frequently used system
resourcegenerating tools available on the Linux platform are vmstat
netstat iostat ifstat mpstat. These are used for reporting statis tics
from differentsystem components such as virtual memory, network
connections and interfaces,CPU, input/output devices and more.
Question: What is Dstat In
Linux
dstatis a powerful,flexible and versatile
toolfor generating Linux system resource statis tics,that is a
replacement for all the tools mentioned in above question. 31/71 It
comes with extra features, counters and it is highlyextensible, users
with Python knowledge can build their own plugins. Features of dstat:
Joins information from vmstat, netstat, iostat, ifstat and mpstattools
Dis plays statis tics simultaneously Orders counters and
highly-extensible Supports summarizing of grouped block/network devices
Dis plays interrupts per device Works on accurate timeframes, no
timeshifts when a system is stressed Supports colored output, it
indicates different units indifferent colors Shows exact units and
limits conversion mis takes as much aspossible Supports exporting of CSV
output to Gnumeric and Exceldocuments
Question: Types Of Processes
In Linux
There are fundamentally two types of processes
inLinux: Foreground processes(also referred to as interactive
processes)– these are initialized and controlled through aterminal
session. In other words, there has to be a user connected to the
systemto start such processes; they haven’t started automatically as
part of thesystem functions/services. Background processes(also referred
to as non-interactive/automaticprocesses) – are processes not connected
to aterminal; they don’t expect any user input.
Question: Creatin Of
Processes In Linux
A new process is normally created when an exis
ting processmakes an exact copy of itself in memory. The child process
will have the same environment as itsparent, but only the process ID
number is different. There are two conventional ways used for creating a
newprocess in Linux: Using The System()Function – this method is
relativelysimple, however, it’s inefficient and hassignificantly certain
security ris ks. Using fork() andexec() Function – this technique is
alittle advanced but offers greater flexibility, speed,together with
security.
Question: Creation Of
Processes In Linux
32/71 Because Linux is a multi-user system,
meaning differentusers can be running various programs on the system,
each running instance of aprogram must be identified uniquely by the
kernel. And a program is identified by its process ID(PID) as well
asit’s parent processes ID (PPID), therefore processes canfurther be
categorized into: Parent processes– these are processes that create
otherprocesses during run- time. Child processes– these processes are
created by otherprocesses during run-time.
Question: What is Init
Process Linux
lnitprocess is the mother (parent) of all
processes on the system,it’s the first program that is executed when the
Linux system bootsup; it manages all other processes on the system. It
is started by thekernel itself, so in principle it does not have a
parent process. The init process always has process ID of1. It functions
as anadoptive parent for all orphaned processes. You can use thepidof
commandto find the ID of a process: # pidof systemd # pidof top # pidof
httpd Find Linux Process ID To find the process ID and parent process ID
of the currentshell, run: $ echo $$ $ echo $PPID
Question: What Are Different
States Of A Processes InLinux
During execution, a process changes from one
state toanother depending on its environment/circumstances. In Linux, a
process has thefollowing possible states: Running– here it’s either
running (it is thecurrent process in the system) or it’s ready to
run(it’s waiting to be assigned to one of the CPUs). Waiting– in this
state, a process is waiting foran event to occur or for a system
resource. Additionally,the kernel also differentiates between two types
of waiting processes;interruptible waiting processes – can be
interrupted by signals anduninterruptible waiting processes – are
waiting directly on hardwareconditions and cannot be interrupted by any
event/signal. Stopped– in this state, a process has beenstopped, usually
by receiving a signal. For instance, a process that is being debugged.
33/71 Zombie– here, a process is dead, it has beenhalted but it’s still
has an entry in the processtable.
Question: How To View Active
Processes In Linux +
There are several Linux tools for viewing/lis
ting runningprocesses on the system, the two traditional and well known
are ps andtop commands: ps Command It dis plays information about a
selection of the activeprocesses on the system as shown below: #ps #ps
-e ] head top – System Monitoring Tool top is a powerful toolthat offers
you a dynamic real-timeview of a running system as shown in the
screenshot below: #top glances – System Monitoring Tool glancesis
arelatively new system monitoring toolwith advanced features: #glances
Question: How To
ControlProcess
Linux also has some commands for controlling
processes suchas kill, pkill, pgrep and killall, below are a few basic
examples of how to usethem: $ pgrep -u tecmint top $ kill 2308 $ pgrep
-u tecmint top $ pgrep -u tecmint glances $ pkill glances $ pgrep -u
tecmint glances
Question: Can We Send signals
To Processes In Linux
The fundamental way of controlling processes in
Linux is bysending signals to them. There are multiple signals that you
can send to aprocess, to view all the signals run: 34/71 $ kill -l Lis t
All Linux Signals To send a signal to a process, use the kill, pkill or
pgrepcommands we mentioned earlier on. But programs can only respond to
signals ifthey are programmed to recognize those signals. And most
signals are for internal use by the system, or forprogrammers when they
write code. The following are signals which are useful toa system user:
SIGHUP 1– sent to a process when its controllingterminal is closed.
SIGINT 2– sent to a process by its controllingterminal when a user
interrupts the process by pressing [Ctrl+C] . SIGQUIT 3– sent to a
process if the user sends aquit signal SIGKILL 9– this signal
immediately terminates(kills) a process and the process will not perform
anyclean-up operations. SIGTERM 15– this a program termination signal
(killwill send this by default). SIGTSTP 20– sent to a process by its
controllingterminal to request it to stop (terminal stop); initiated by
the userpressing
Question: How To Change
Priority Of A Processes InLinux
On the Linux system, all active processes have
a priorityand certain nice value. Processes with higher priority will
normally get moreCPU time than lower priority processes. However, a
system user with root privileges can influencethis with thenice
andrenicecommands. From the output of the top command, the NI shows the
processnice value: $ top Lis t Linux Running Processes Use
thenicecommand to set a nice value for a process. Keepin mind that
normal users can attribute a nice value from zero to 20 toprocesses they
own. Only the root user can use negative nice values. Torenicethe
priority of a process, use therenice command asfollows: $ renice +8 2687
$ renice +8 2103 GIT DevOps Interview Questions
Question: What is Git
35/71 Git is a version controlsystem for
tracking changes incomputer files and coordinating work on those files
among multiplepeople. It is primarily used for source code management in
softwaredevelopment but it can be used to keep track of changes in any
set offiles. As a dis tributed revis ion controlsystem it is aimed
atspeed, data integrity, and support for dis tributed, non-linear
workflows. By far, the most widely used modern version controlsystemin
the world today is Git. Git is a mature, actively maintained open
sourceproject originally developed in 2005 by Linus Torvald. Git is an
example of aDis tributed Version ControlSystem, In Git, every
developer's working copyof the code is also a repository that can
contain the full his tory of allchanges.
Question: What Are Benefits
Of GIT
Here are some of the advantages of using Git
Ease of use Data redundancy andreplication High availability Superior
dis k utilization andnetwork performance Only one .git directory
perrepository Collaboration friendly Any kind of projects fromlarge to
small scale can use GIT
Question: What is Repository
In GIT
The purpose of Git is to manage a project, or a
set offiles, as they change over time. Git stores this information in a
data structurecalled a repository. A gitrepository contains, among other
things, thefollowing: A set ofcommit objects. A set of references to
commitobjects, called heads. The Git repository is stored in the same
directory as theproject itself, in a subdirectory called .git . Note
differences from central-repository systems like CVS orSubversion: There
is only one .git directory, in the root directory of theproject. The
repository is stored infiles alongside the project. There is no central
server repository.
Question: What is Staging
Area In GIT
36/71 Staging is a step before the commit
process in git. That is ,a commit in git is performed in two steps:
-Staging and -Actual commit As long as a change set is in the staging
area, git allowsyou to edit it as you like (replace staged files with
other versions of staged files,remove changes from staging, etc.)
Question: What is GIT STASH
Often, when you’ve been working on part of
yourproject, things are in a messy state and you want to switch branches
for a bitto work on something else. The problem is , you don’t want to
do a commit ofhalf-done work just so you can get back to this point
later. The answer to this is sue is the git stash command.Stashing takes
the dirty state of your working directory — that is , yourmodified
tracked files and staged changes — and saves it on a stack ofunfinis hed
changes that you can reapply at any time.
Question: How To Revert
Commit In GIT
Given one or more exis ting commits, revert the
changes thatthe related patches introduce, and record some new commits
that record them.This requires your working tree to be clean (no
modifications from the HEADcommit). git-revert - Revert some exis ting
commits SYNOPSis git revert [--[no-]edit] [-n] [-m parent-number]
[-s][-S[ ]] … git revert --continue git revert --quit
git revert --abort
Question: How To Delete
Remote Repository In GIT
Use the git remote rm command to remove a
remote URL from your repository. The git remote rm command takes one
argument: A remote name, for example,
Questions: What is GIT Stash
Drop
37/71 In case we do not need a specific stash,
we use git stashdrop command to remove it from the lis t of stashes. By
default, this command removes to latest addedstash To remove a specific
stash we specify as argument in the gitstash drop command.
Question: What is Difference
Between GIT andSubversion
Here is a summary of Differences between GIT
andSubversion Git is a dis tributed VCS; SVNis a non-dis tributed VCS.
Git has a centralized serverand repository; SVN does not have a
centralized server orrepository. The content in Git is storedas
metadata; SVN stores files of content. Git branches are easier towork
with than SVN branches. Git does not have the globalrevis ion number
feature like SVN has. Git has better contentprotection than SVN. Git was
developed for Linuxkernel by Linus Torvalds; SVN was developed by
CollabNet,Inc. Git is dis tributed under GNU,and its maintenance
overseen by Junio Hamano; Apache Subversion, or SVN, is dis tributed
under theopen source license.
Question: What is Difference
Between GIT Fetch & GITPull
GIT fetch – It downloads only the new data from
theremote repository and does not integrate any of the downloaded data
into yourworking files. Providing a view of the data is all it does. GIT
pull – It downloads as well as merges the datafrom the remote repository
into the local working files. This may also lead to merging conflicts if
the user’slocal changes are not yet committed. Using the “GIT stash”
commandhides the local changes.
Question:What is Git forkHow
to create tag
A fork is a copy of a repository. Forking a
repositoryallows you to freely experiment with changes without affecting
the originalproject. A fork is really a Github (not Git) construct to
store aclone of the repo in your user account. As a clone, it will
contain all thebranches in the main repo at the time you made the fork.
38/71 Create Tag: Click the releases link on ourrepository page. Click
on Create a new releaseor Draft a new release. Fill out the form fields,
thenclick Publis h release at the bottom. After you create your tag
onGitHub, you might want to fetch it into your local repository too: git
fetch.
Question: What is difference
between fork andbranch
A fork is a copy of a repository. Forking a
repositoryallows you to freely experiment with changes without affecting
the originalproject. A fork is really a Github (not Git) construct to
store aclone of the repo in your user account. As a clone, it will
contain all thebranches in the main repo at the time you made the fork.
Question: What is Cherry
Picking In GIT
Cherry picking in git means to choose a commit
from onebranch and apply it onto another. This is in contrast with other
ways such as merge and rebasewhich normally applies many commits onto a
another branch. Make sure you are on the branch you want apply the
committo. git checkout master Execute the following: git cherry-pick
Question: What Language GIT
is Written In
Much of Git is written in C, along with some
BASH scriptsfor UI wrappers and other bits.
Question: How To Rebase
Master In GIT
Rebasing is the process of moving a branch to a
new basecommit.The golden rule of git rebase is to never use it on
publicbranches. The only way to synchronize the two master branches is
tomerge them back together, resulting in an extra merge commit and two
sets ofcommits that contain the same changes.
Question: What is ‘head’in
git and how many heads can be created in a repository
image 39/71 There can be any number of heads in
a GIT repository. Bydefault there is one head known as HEAD in each
repository in GIT. HEADis a ref(reference) to the currently checked out
commit. In normal states, it'sactually a symbolic ref to the branch user
has checked out. if you look at the contents of .git/HEAD you'll see
something like"ref: refs/heads/master". The branch itself is a reference
to the commit at thetip of the branch
Question: Name some GIT
commands and also explain theirfunctions
Here are some most important GIT commands GIT
diff– It shows the changes between commits,commits and working tree. GIT
status– It shows the difference between workingdirectories and index.
GIT stash applies– It is used to bring back the savedchanges on the
working directory. GIT rm– It removes the files from the stagingarea and
also of the dis k. GIT log– It is used to find the specific commit inthe
his tory. GIT add– It adds file changes in the exis tingdirectory to the
index. GIT reset– It is used to reset the index and as wellas the
working directory to the state of the lastcommit. GIT checkout– It is
used to update the directories ofthe working tree with those from
another branch withoutmerging. GIT is tree– It represents a tree object
including themode and the name of each item. GITinstaweb – It
automatically directs a webbrowser and runs the web server with an
interface intoyour local repository.
Question: What is a
“conflict” in GIT and how is it resolved
When a commit that has to be merged has some
changes in oneplace, which also has the changes of current commit, then
the conflictaris es. The GIT will not be able to predict which change
will takethe precedence. In order to resolve the conflict in GIT: we
have to edit thefiles to fix the conflicting changes and then add the
resolved files by runningthe “GIT add” command; later on, to commit the
40/71 repaired merge run the “GIT commit” command.GIT identifies the
position and sets the parents of the commit correctly.
Question: How To Migrate From
Subversion To GIT +
SubGITis a toolforsmooth and stress-free
subversion to GIT migration and also a solution for acompany-wide
subversion to GIT migration that is : It allows to make use of allGIT
and subversion features. It provides genuinestress-free migration
experience. It doesn’t require anychange in the infrastructure that is
already placed. It is considered to be muchbetter than GIT-SVN
Question: What is Index In
GIT
The index is a single, large, binary file in
under .gitfolder, which lis ts all files in the current branch, their
sha1 checksums, timestamps and the file name. Before completing the
commits, it is formatted andreviewed in an intermediate area known as
Index also known as the stagingarea.
Question: What is a bare Git
repository
A bare Git repository is a repository that is
createdwithout a Working Tree. git init --bare
Question: WHow do you revert
a commit that has already beenpushed and made public
One or more commits can be reverted through the
use of git revert . This command, inessence, creates a new commit with
patches that cancel out the changesintroduced in specific commits. In
case the commit that needs to be reverted has alreadybeen publis hed or
changing the repository his tory is not an option, git revert can be
used torevert commits. Running the following command will revert the
last twocommits: git revert HEAD~2..HEAD 41/71 Alternatively, one can
always checkout the state of aparticular commit from the past, and
commit it anew.
Question: How do you squash
last N commits into a singlecommit
Squashing multiple commits into a single commit
willoverwrite his tory, and should be done with caution. However, this
is useful whenworking in feature branches. To squash the last N commits
of the current branch, run thefollowing command (with {N} replaced with
the number of commits that you want tosquash): git rebase -i HEAD~{N}
Upon running this command, an editor will open with a lis tof these N
commit messages, one per line. Each of these lines will begin with the
word“pick”. Replacing “pick” with “squash” or“s” will tell Git to
combine the commit with the commit beforeit. To combine all N commits
into one, set every commit in thelis t to be squash except the first
one. Upon exiting the editor, and if no conflict aris es, git rebase
will allow you tocreate a new commit message for the new combined
commit.
Question: What is a conflict
in git and how can it beresolved
A conflict aris es when more than one commit
that has to bemerged has some change in the same place or same line of
code. Git will not be able to predict which change should
takeprecedence. This is a git conflict. To resolve the conflict in git,
edit the files to fix theconflicting changes and then add the resolved
files by running After that, to commit the repaired merge, run remembers
thatyou are in the middle of a merge, so it sets the parents of the
commitcorrectly.
Question: How To Setup A
Script To Run Every Time aRepository Receives New Commits Through
Push
42/71 To configure a script to run every time a
repositoryreceives new commits through push, one needs to define either
a pre-receive,update, or a post-receive hook depending on when exactly
the script needs to betriggered. Pre-receive hook in the destination
repository is invokedwhen commits are pushed to it. Any script bound to
this hook will be executedbefore any references are updated. This is a
useful hook to run scripts that help enforcedevelopment policies. Update
hook works in a similar manner to pre-receive hook,and is also triggered
before any updates are actually made. However, the update hook is called
once for every committhat has been pushed to the destination repository.
Finally, post-receive hook in the repository is invokedafter the updates
have been accepted into the destination repository. This is an ideal
place to configure simple deploymentscripts, invoke some continuous
integration systems, dis patch notificationemails to repository
maintainers, etc. Hooks are local to every Git repository and are
notversioned. Scripts can either be created within the hooks directory
inside the“.git” directory, or they can be created elsewhere and links
tothose scripts can be placed within the directory.
Question: What is Commit Hash
In Git each commit is given a unique hash.
These hashes canbe used to identify the corresponding commits in various
scenarios (such aswhile trying to checkout a particular state of the
code using the git checkout {hash} command). Additionally, Git also
maintains a number of aliases tocertain commits, known as refs. Also,
every tag that you create in the repositoryeffectively becomes a ref
(and that is exactly why you can use tags instead ofcommit hashes in
various git commands). Git also maintains a number of special aliases
that changebased on the state of the repository, such as HEAD,
FETCH_HEAD, MERGE_HEAD,etc. Git also allows commits to be referred as
relative to oneanother. For example, HEAD~1 refers to the commit parent
to HEAD, HEAD~2 refersto the grandparent of HEAD, and so on. In case of
merge commits, where the commit has two parents,^ can be used to select
one of the two parents, e.g. HEAD^2 can be used tofollow the second
parent. And finally, refspecs. These are used to map local andremote
branches together. However, these can be used to refer to commits that
resideon remote branches allowing one to controland manipulate them from
a local Gitenvironment. 43/71 image
Question: What is Conflict In
GIT
A conflict aris es when more than one commit
that has to bemerged has some change in the same place or same line of
code. Git will not be able to predict which change should
takeprecedence. This is a git conflict.To resolve the conflict in git,
edit thefiles to fix the conflicting changes and then add the resolved
files by running git add . After that, to commit therepaired merge, run
git commit . Gitremembers that you are in the middle of a merge, so it
sets the parents of thecommit correctly.
Question:What are githooks
Git hooks are scripts that can run
automatically on theoccurrence of an event in a Git repository. These
are used for automation ofworkflow in GIT. Git hooks also help in
customizing the internal behavior ofGIT. These are generally used for
enforcing a GIT commit policy.
Question: What Are Dis
advantages Of GIT
GIT has very few dis advantages. These are the
scenarios whenGIT is difficult to use. Some of these are: Binary
Files:If wehave a lot binary files (non-text) in our project, then GIT
becomes very slow.E.g. Projects with a lot of images or Word documents.
Steep Learning Curve:It takes some time for a newcomer to learn GIT.
Some of the GITcommands are non-intuitive to a fresher. Slow remote
speed:Sometimes the use of remote repositories in slow due to
networklatency. Still GIT is better than other VCS in speed. image
Question: What is stored
inside a commit object inGIT
GIT commit object contains following
information: SHA1 name:A 40character string to identify a commit
Files:Lis t of filesthat represent the state of a project at a specific
point of time Reference:Anyreference to parent commit objects 44/71
Question: What is GIT reset
command
Git reset command is used to reset current HEAD
to aspecific state. By default it reverses the action of git add
command. So we usegit reset command to undo the changes of git add
command. Reference: Anyreference to parent commit objects
Question:How GIT protects the
code in arepository
GIT is made very secure since it contains the
source code ofan organization. All the objects in a GIT repository are
encrypted with ahashing algorithm called SHA1. This algorithm is quite
strong and fast. It protects sourcecode and other contents of repository
against the possible maliciousattacks. This algorithm also maintains the
integrity of GITrepository by protecting the change his tory against
accidental changes. Continuos Integration Interview Questions
Question: What is Continuos
Integration
Continuous Integration is the process of
continuouslyintegrating the code and often multiple times per day. The
purpose is to findproblems quickly, s and deliver the fixes more
rapidly. CI is a best practice for software development. It is doneto
ensure that after every code change there is no is sue in software.
Question: What is Build
Automation
image Build automation is the process of
automating the creationof a software build and the associated processes.
Including compiling computer source code into binary code,packaging
binary code, and running automated tests.
Question: What is Automated
Deployment
Automated Deployment is the process of consis
tently pushinga product to various environments on a “trigger.” 45/71 It
enables you to quickly learn what to expect every timeyou deploy an
environment with much faster results. This combined with Build
Automation can save developmentteams a significant amount of hours.
Automated Deployment saves clients from being extensivelyoffline during
development and allows developers to build while“touching” fewer of a
clients’ systems. With an automated system, human error is prevented. In
theevent of human error, developers are able to catch it before live
deployment– saving time and headache. You can even automate the
contingency plan and make the siterollback to a working or previous
state as if nothing ever happened. Clearly, this automated feature is
super valuable inallowing applications and sites to continue during
fixes. Additionally, contingency plans can be
version-controlled,improved and even self-tested.
Question: How Continuous
Integration Implemented
Different tools for supporting Continuous
Integration areHudson, Jenkins and Bamboo. Jenkins is the most popular
one currently. Theyprovide integration with various version
controlsystems and build tools.
Question: How Continuous
Integration process doeswork
Whenever developer commits changes in version
controlsystem, then Continuous Integration server detects that changes
are committed.And goes through following process Continuous Integration
serverretrieves latest copy of changes. It build code with new changesin
build tools. If build fails notify todeveloper. After build pass run
automatedtest cases if test cases fail notify to developer. Create
package for deploymentenvironment.
Question: What Are The
Software Required For ContinuousIntegration process
image Here are the minimum tools you need to
achieve CI Source code repository : Tocommit code and changes for
example git. Server: It is ContinuousIntegration software for example
Jenkin, Teamcity. 46/71 Build tool: It buildsapplication on particular
way for example maven, gradle. Deployment environment : Onwhich
application will be deployed.
Question:What is
JenkinsSoftware
Jenkins is self-contained, open source
automation serverused to automate all sorts of tasks related to
building, testing, and deliveringor deploying software. Jenkins is one
of the leading open source automation serversavailable. Jenkins has an
extensible, plugin-based architecture, enablingdevelopers to create
1,400+ plugins to adapt it to a multitude of build, testand deployment
technology integrations.
Questions: What is a Jenkins
Pipeline
Jenkins Pipeline (or simply “Pipeline”) is
asuite of plugins which supports implementing and integrating continuous
deliverypipelines into Jenkins..
Question: What is the
differencebetween Maven, Ant,Gradle and Jenkins
Maven and Ant are Build Technologies whereas
Jenkins is acontinuous integration tool.
Question:Why do we useJenkins
Jenkins is anopen-sourcecontinuous integration
software toolwritten inthe Java programming language for testing and
reporting on is olated changes in alarger code base in real time.
TheJenkins softwareenables developers to find and solve defects in acode
base rapidly and to automate testing of their builds.
Question:What are CITools
Here is the lis t of the top 8Continuous
Integration tools: Jenkins TeamCity Travis CI Go CD Bamboo GitLab CI
47/71 CircleCI Codeship
Question:Which SCM
toolsJenkins supports
Jenkins supports version controltools,
including AccuRev,CVS, Subversion, Git, Mercurial, Perforce, ClearCase
and RTC, and can executeApache Ant, Apache Maven and arbitrary shell
scripts and Windows batchcommands.
Question:Why do we
usePipelines in Jenkins
Pipeline adds a powerful set of automation
tools ontoJenkins, supporting use cases that span from simple continuous
integration tocomprehensive continuous delivery pipelines. By modeling a
series of related tasks, users can takeadvantage of the many features of
Pipeline: Code: Pipelines areimplemented in code and typically checked
into source control, giving teams theability to edit, review, and
iterate upon their delivery pipeline. Durable: Pipelines can surviveboth
planned and unplanned restarts of the Jenkins master. Pausable:
Pipelines canoptionally stop and wait for human input or approval before
continuing the Pipeline run. Versatile: Pipelines supportcomplex
real-world continuous delivery requirements,including the ability to
fork/join, loop, and perform work in parallel. Extensible: The
Pipelineplugin supports custom extensions to its DSL and multiple
options forintegration with other plugins.
Question: How do you
createMultibranch Pipeline in Jenkins
The Multi branch Pipeline project type enables
you toimplement different Jenkins files for different branches of the
sameproject. In a Multi branch Pipeline project, Jenkins
automaticallydis covers, manages and executes Pipelines for branches
which contain a Jenkinsfile in source control.
Question:What are Jobs
inJenkins
Jenkinscan be usedto perform the typical build
server work, such as doingcontinuous/official/nightly builds, run tests,
or perform some repetitive batchtasks. This is called “free-style
softwareproject” in Jenkins. 48/71
Question:How do you
configuringautomatic builds in Jenkins
Builds in Jenkinscanbe triggered periodically
(on a schedule, specified in configuration), or whensource changes in
the project have been detected, or they can be automaticallytriggered by
requesting the URL:
Question:What is a
Jenkinsfile
Jenkins file is a text file containing the
definition of aJenkins Pipeline and checks into source control. Amazon
AWS DevOps Interview Questions
Question: What is Amazon
WebServices
Amazon Web Services provides services that help
you practiceDevOps at your company and that are built first for use with
AWS. These tools automate manual tasks, help teams manage
complexenvironments at scale, and keep engineers in controlof the high
velocity thatis enabled by DevOps
Question: What Are Benefits
Of AWS for DevOps
There are many benefits of using AWS for devops
Get Started Fast:Each AWS service is ready to use if you have an AWS
account. There is no setup required or software to install. Fully
Managed Services:These services can help you take advantage of AWS
resources quicker.You can worry less about setting up, installing, and
operating infrastructure onyour own. This lets you focus on your core
product. Built For Scalability:You can manage a single instance or scale
to thousands using AWSservices. These services help you make the most of
flexible compute resources bysimplifying provis ioning, configuration,
and scaling. Programmable:Youhave the option to use each service via the
AWS Command Line Interface orthrough APis and SDKs. You can also model
and provis ion AWS resources and yourentire AWS infrastructure using
declarative AWS CloudFormation templates. Automation:AWS helpsyou use
automation so you can build faster and more efficiently. Using
AWSservices, you can automate manual tasks or processes such as
deployments, 49/71 development & test workflows, container management,
andconfiguration management. Secure:Use AWSIdentity and Access
Management (IAM) to set user permis sions and policies. This gives you
granular controlover who can access your resources and how theyaccess
those resources.
Question: How To Handle
ContinuousIntegration and Continuous Delivery in AWS Devops
The AWS Developer Tools help in securely store
and versionyour application’s source code and automatically build, test,
and deployyour application to AWS.
Question: What is The
Importance Of Buffer In Amazon WebServices
image An Elastic Load Balancer ensures that the
incoming trafficis dis tributed optimally across various AWS instances.
A buffer will synchronize different components and makes thearrangement
additional elastic to a burst of load or traffic. The components are
prone to work in an unstable way ofreceiving and processing the
requests. The buffer creates the equilibrium linking various
apparatusand crafts them effort at the identical rate to supply more
rapidservices.
Question: What Are The
Components Involved In Amazon WebServices
image There are 4 components Amazon S3:
withthis , one can retrieve the key information which are occupied in
creating cloudstructural design and amount of produced information also
can be stored in this component that is the consequence of the key
specified. Amazon EC2 instance:helpful to run a large dis tributed
system on the Hadoop cluster. Automaticparallelization and job
scheduling can be achieved by this component. Amazon SQS: this component
acts as a mediator between different controllers. Also worn
forcushioning requirements those are obtained by the manager of Amazon.
Amazon SimpleDB:helps in storing the transitional position log and the
errands executed by theconsumers. 50/71 image
Question: How is a Spot
instance different from anOn-Demand instance or Reserved Instance
image Spot Instance, On-Demand instance and
Reserved Instances areall models for pricing. Moving along, spot
instances provide the ability forcustomers to purchase compute capacity
with no upfront commitment, at hourlyrates usually lower than the
On-Demand rate in each region. Spot instances are just like bidding, the
bidding price is called Spot Price. The Spot Price fluctuates based on
supply and demand forinstances, but customers will never pay more than
the maximum price they havespecified. If the Spot Price moves higher
than a customer’smaximum price, the customer’s EC2 instance will be shut
downautomatically. But the reverse is not true, if the Spot prices come
downagain, your EC2 instance will not be launched automatically, one has
to do thatmanually. In Spot and On demand instance, there is no
commitment forthe duration from the user side, however in reserved
instances one has to stickto the time period that he has chosen.
Questions: What are the best
practicesfor Security in Amazon EC2
There are several best practices to secure
Amazon EC2. A fewof them are given below: Use AWS Identity and
AccessManagement (IAM) to controlaccess to your AWS resources. Restrict
access by onlyallowing trusted hosts or networks to access ports on
yourinstance. Review the rules in yoursecurity groups regularly, and
ensure that you apply theprinciple of least Privilege – only open
uppermis sions that you require. Dis able password-based loginsfor
instances launched from your AMI. Passwords can befound or cracked, and
are a security ris k.
Question:What is AWSCodeBuild
in AWSDevops
AWS CodeBuild is a fully managed build service
that compilessource code, runs tests, and produces software packages
that are ready todeploy. With CodeBuild, you don’t need to provis ion,
manage,and scale your own build servers. CodeBuild scales continuously
and processesmultiple builds concurrently, so your builds are not left
waiting in aqueue. 51/71
Question:What is
AmazonElastic Container Service in AWSDevops
Amazon Elastic Container Service (ECS) is a
highly scalable,high performance container management service that
supports Docker containersand allows you to easily run applications on a
managed cluster of Amazon EC2instances.
Question:What is AWS Lambdain
AWS Devops
AWS Lambda lets you run code without provis
ioning ormanaging servers. With Lambda, you can run code for virtually
any type ofapplication or backend service, all with zero adminis
tration. Just upload your code and Lambda takes care of
everythingrequired to run and scale your code with high availability.
Splunk DevOps Interview Questions
Question: What is Splunk
The platform of Splunk allows you to get vis
ibility intomachine data generated from different networks, servers,
devices, andhardware. It can give insights into the application
management, threatvis ibility, compliance, security, etc. so it is used
to analyze machine data.The data is collected from the forwarder from
the source and forwarded to theindexer. The data is stored locally on a
host machine or cloud. Then on the datastored in the indexer the search
head searches, vis ualizes, analyzes andperforms various other
functions.
Question: What Are The
Components Of Splunk
The main components of Splunk are Forwarders,
Indexers andSearch Heads.Deployment Server(or Management Console Host)
will come into thepicture in case of a larger environment. Deployment
servers act like an antivirus policy server forsetting up Exceptions and
Groups so that you can map and create adifferent setof data collection
policies each for either window based server or a Linux basedserver or a
Solaris based server.plunk has fourimportant components : Indexer –It
indexes the machine data Forwarder –Refers to Splunk instances that
forward data tothe remote indexers Search Head –Provides GUI for
searching Deployment Server– Manages the Splunk components likeindexer,
forwarder, and 52/71 search head in computing environment.
Question:What are alerts
inSplunk
An alert is an action that a saved search
triggers onregular intervals set over a time range, based on the results
of thesearch. When the alerts are triggered, various actions
occurconsequently.. For instance, sending an email when a search to the
predefinedlis t of people is triggered. Three types of alerts:
Pre-result alerts :Mostcommonly used alert type and runs in real-time
for an all- time span. Thesealerts are designed such that whenever a
search returns a result, they aretriggered. Scheduled alerts :Thesecond
most common- scheduled results are set up to evaluate the results ofa
his torical search result running over a set time range on a
regularschedule. You can define a time range, schedule and the trigger
condition toan alert. Rolling-window alerts:These are the hybrid of
pre-result and scheduled alerts. Similar tothe former, these are based
on real-time search but do not trigger each timethe search returns a
matching result . It examines all events in real-timemapping within the
rolling window and triggers the time that specificcondition by that
event in the window is met, like the scheduled alert is triggered on a
scheduled search.
Question: What Are The
Categories Of SPL Commands
SPL commands are divided into five categories:
Sorting Results –Ordering results and (optionally) limiting the number
ofresults. Filtering Results –It takes a set of events or results and
filters them into a smallerset of results. Grouping Results –Grouping
events so you can see patterns. Filtering, Modifying and Adding Fields
–Taking search results and generating asummary for reporting. Reporting
Results –Filtering out some fields to focus on the ones you need,
ormodifying or adding fields to enrich your results or events.
Question: What Happens If The
LicenseMaster is Unreachable
In case the license master is unreachable, then
it is justnot possible to search the data. 53/71 However, the data
coming in to the Indexer will not beaffected. The data will continue to
flow into your Splunk deployment. The Indexers will continue to index
the data as usualhowever, you will get a warning message on top your
Search head or web UI sayingthat you have exceeded the indexing volume.
And you either need to reduce the amount of data coming inor you need to
buy a higher capacity of license. Basically, the candidate is expected
to answer that the indexing does not stop; only searching is halted
Question: What are common
port numbers used bySplunk
Common port numbers on which default services
runare: Service PortNumber Splunk Management Port 8089 Splunk Index
Replication Port 8080 KV store 8191 Splunk Web Port 8000 Splunk Indexing
Port 9997 Splunk network port 514
Question: What Are Splunk
BucketsExplain The BucketLifecycle
image A directory that contains indexed data is
known as a Splunkbucket. It also contains events of a certain period.
Bucket lifecycle includesfollowing stages: Hot –It contains newly
indexed data and is open forwriting. For each index, there are one or
more hot buckets available Warm –Data rolled from hot Cold –Data rolled
from warm Frozen –Data rolled from cold. The indexer deletes frozendata
by default but users can also archive it. Thawed –Data restored from an
archive. If you archivefrozen data , you can later return it to the
index bythawing (defrosting) it.
Question:Explain Data
Modelsand Pivot
54/71 Data models are used for creating a
structured hierarchicalmodel of data. It can be used when you have a
large amount of unstructured data,and when you want to make use of that
information without using complex searchqueries. A few use cases of Data
models are: Create Sales Reports:If you have a sales report, then you
can easilycreate the total number of successful purchases, belowthat you
can create a child object containing the lis t of failed purchases
andother views Set Access Levels:If you want a structured view of users
and theirvarious access levels, you can use a data model On the other
hand with pivots, you have the flexibility tocreate the front views of
your results and then pick and choose the mostappropriate filter for a
better view of results.
Question: What is
FilePrecedence In Splunk
File precedence is an important aspect of
troubleshooting inSplunk for an adminis trator, developer, as well as an
architect. All of Splunk’s configurations are written in .conffiles.
There can be multiple copies present for each of these files, and thus
itis important to know the role these files play when a Splunk instance
is runningor restarted. To determine the priority among copies of a
configuration file,Splunk software first determines the directory
scheme. The directory schemes areeither a) Global or b) App/user. When
the context is global (that is , wherethere’s no app/user context),
directory priority descends in this order: System local directory —
highestpriority App local directories App default directories System
default directory — lowestpriority When the context is app/user,
directory priority descendsfrom user to app to system: User directories
for current user — highest priority App directories for currently
running app (local, followed bydefault) App directories for all other
apps (local, followed by default)— for exported settings only System
directories (local, followed by default) — lowest priority
Question: D ifference Between
SearchTime And Index Time Field Extractions
image Search time field extraction refers to
the fields extractedwhile performing searches. Whereas, fields extracted
when the data comes to the indexerare referred to as Index time field
extraction. 55/71 You can set up the indexer time field extraction
either atthe forwarder level or at the indexer level. Another difference
is that Search time fieldextraction’s extracted fields are not part of
the metadata, so they do notconsume dis k space. Whereas index time
field extraction’s extracted fieldsare a part of metadata and hence
consume dis k space.
Question:What is Source
TypeIn Splunk
Source type is a default field which is used to
identify thedata structure of an incoming event. Source type determines
how SplunkEnterpris e formats the data during the indexing process.
Source type can be set at the forwarder level for indexerextraction to
identify different data formats.
Question: What is SOS
SOS stands for Splunk on Splunk. It is a Splunk
app thatprovides graphical view of your Splunk environment performance
andis sues. It has following purposes: Diagnostic toolto analyze
andtroubleshoot problems Examine Splunk environmentperformance Solve
indexing performanceis sues Observe scheduler activitiesand is sues See
the details of schedulerand user driven search activity image Search,
view andcompare configuration files of Splunk
Question: What is Splunk
Indexer And Explain ItsStages
The indexer is a Splunk Enterpris e component
that createsand manages indexes. The main functions of an indexer are:
Indexing incoming data Searching indexed dataSplunk indexer has
following stages: Input :SplunkEnterpris e acquires the raw data from
various input sources and breaks it into64K blocks and assign them some
metadata keys. These keys include host, sourceand source type of the
data.Parsing :Also known as event processing, during this stage, the
Enterpris e analyzes and transforms the data, breaks data intostreams,
identifies, parses and sets timestamps, performs metadata annotationand
transformation of data. Indexing :In this phase, the parsed events are
written onthe dis k index including both compressed data and the
associated index files.Searching : The‘Search’ function plays a 56/71
major role during this phase as it handles all searchingaspects
(interactive, scheduled searches, reports, dashboards, alerts) on
theindexed data and stores saved searches, events, field extractions
andviews
Question: State The
Difference Between Stats andEventstats Commands
Stats –This command produces summary statis
tics of all exis ting fields in your searchresults and store them as
values in new fields.Eventstats – It is same asstats command except that
aggregation results are added in order to every eventand only if the
aggregation is applicable to that event. It computes therequested statis
tics similar to stats but aggregates them to the original rawdata. log4J
DevOps Interview Questions
Question: What is log4j
log4j is a reliable, fast and flexible logging
framework(APis ) written in Java, which is dis tributed under the Apache
SoftwareLicense. log4j has been ported to the C, C++, C#, Perl, Python,
Ruby,and Eiffel languages. log4j is highly configurable through external
configurationfiles at runtime. It views the logging process in terms of
levels of prioritiesand offers mechanis ms to direct logging information
to a great variety ofdestinations. Question:What Are TheFeatures Of
Log4j Log4j is widely used framework and here are features oflog4j It is
thread-safe.It is optimized for speed It is based on a named
loggerhierarchy. It supports multiple outputappenders per logger. It
supportsinternationalization. It is not restricted to apredefined set of
facilities. Logging behavior can be set atruntime using a configuration
file. It is designed to handle JavaExceptions from the start. It uses
multiple levels,namely ALL, TRACE, DEBUG, INFO, WARN, ERROR and FATAL.
The format of the log outputcan be easily changed by extending the
Layout class. The target of the log outputas well as the writing
strategy can be altered by implementations of the Appender interface. It
is fail-stop. However,although it certainly strives to ensure delivery,
log4j does not 57/71 guarantee that each log statement will be delivered
to itsdestination.
Question: What are the
components oflog4j
log4j has three main components loggers:
Responsible forcapturing logging information. appenders: Responsible
forpublis hing logging information to various preferred destinations.
layouts: Responsible forformatting logging information in different
styles.
Question: How do you
initialize and use Log4J
public class LoggerTest { static Logger log
=Logger.getLogger (LoggerTest.class.getName()); public void my
logerMethod() {if(log.is DebugEnabled()) log.debug("This is test
message" + var2); ) }}
Question:What are Pros
andCons of Logging
Following are the Pros and Cons of Logging
Logging is animportant component of the software development. A
well-written logging codeoffers quick debugging, easy maintenance, and
structured storage of anapplication's runtime information. Logging does
have its drawbacks also. Itcan slow down an application. If too verbose,
it can cause scrolling blindness.To alleviate these concerns, log4j is
designed to be reliable, fast andextensible. Since logging is rarely the
main focus of an application, the log4jAPI strives to be simple to
understand and to use.
Question: What is The Purpose
OfLogger Object
Logger Object − The top-level layer of
log4jarchitecture is the Logger which provides the Logger object. The
Logger object is responsible for capturing logginginformation and they
are stored in a namespace hierarchy.
Question: What is the purpose
of Layout object
58/71 The layout layer of log4j architecture
provides objectswhich are used to format logging information in
different styles. It providessupport to appender objects before publis
hing logging information. Layout objects play an important role in
publis hing logginginformation in a way that is human-readable and
reusable.
Questions: What is the
purpose of Appender object
The Appender object is responsible for publis
hing logginginformation to various preferred destinations such as a
database, file, console,UNIX Syslog, etc.
Question: What is The Purpose
OfObjectRenderer Object
The ObjectRenderer object is specialized in
providing aString representation of different objects passed to the
loggingframework. This object is used by Layout objects to prepare the
finallogging information.
Question:What is
LogManagerobject
The LogManager object manages the logging
framework. It is responsible for reading the initial configuration
parameters from a system-wideconfiguration file or a configuration
class.
Question: How Will You Define
A FileAppender Using Log4j.properties
image Following syntax defines a file appender
−log4j.appender.FILE=org.apache.log4j.FileAppenderlog4j.appender.FILE.File=${log}/log.out
Question: W hat is The
Purpose OfThreshold In Appender
Appender can have a threshold level associated
with itindependent of the logger level. The Appender ignores any logging
messages thathave a level lower than the threshold level. Docker DevOps
Interview Questions
Question: What is Docker
59/71 image Docker provides a container for
managing software workloadson shared infrastructure, all while keeping
them is olated from oneanother. Docker is a tooldesigned to make it
easier to create,deploy, and run applications by using containers.
Containers allow a developer to package up an applicationwith all of the
parts it needs, such as libraries and other dependencies, andship it all
out as one package. By doing so, the developer can rest assured that
theapplication will run on any other Linux machine regardless of any
customizedsettings that machine might have that could differ from the
machine used forwriting and testing the code. In a way, Docker is a bit
like a virtual machine.But unlike a virtual machine, rather than
creating a whole virtual operatingsystem. Docker allows applications to
use the same Linux kernel as the systemthat they're running on and only
requires applications be shipped withthings not already running on the
host computer. This gives a significantperformance boost and reduces the
size of the application.
Question:What Are
LinuxContainers
Linux containers, in short, contain
applications in a waythat keep them is olated from the host system that
they run on. Containers allow a developer to package up an
applicationwith all of the parts it needs, such as libraries and other
dependencies, andship it all out as one package. And they are designed
to make it easier to provide aconsis tent experience as developers and
system adminis trators move code fromdevelopment environments into
production in a fast and replicable way.
Question: Who is Docker For
Docker is a toolthat is designed to benefit
both developersand system adminis trators, making it a part of many
DevOps (developers +operations) toolchains. For developers, it means
that they can focus on writing codewithout worrying about the system
that it will ultimately be running on. It also allows them to get a head
start by using one ofthousands of programs already designed to run in a
Docker container as a part oftheir application. For operations staff,
Docker gives flexibility andpotentially reduces the number of systems
needed because of its small footprintand lower overhead. 60/71
Question:What is
DockerContainer
Docker containers include the application and
all of itsdependencies, but share the kernel with other containers,
running as is olatedprocesses in user space on the host operating
system. Docker containers are not tied to any specificinfrastructure:
they run on any computer, on any infrastructure, and in anycloud. Now
explain how to create a Docker container, Dockercontainers can be
created by either creating a Docker image and then running itor you can
use Docker images that are present on the Dockerhub. Dockercontainers
are basically runtime instances of Docker images.
Question:What is DockerImage
Docker image is the source of Docker container.
In otherwords, Docker images are used to create containers. Images are
created with the build command, and they’llproduce a container when
started with run. Images are stored in a Docker regis try such asregis
try.hub.docker.com because they can become quite large, images are
designedto be composed of layers of other images, allowing a minimal
amount of data tobe sent when transferring images over the network.
Question:What is DockerHub
Docker hub is a cloud-based regis try service
which allowsyou to link to code repositories, build your images and test
them, storesmanually pushed images, and links to Docker cloud so you can
deploy images toyour hosts. It provides a centralized resource for
container imagedis covery, dis tribution and change management, user and
team collaboration, andworkflow automation throughout the development
pipeline.
Question: What is Docker
Swarm
Docker Swarm is native clustering for Docker.
It turns apoolof Docker hosts into a single, virtual Docker host. Docker
Swarm serves the standard Docker API, any toolthatalready communicates
with a Docker daemon can use Swarm to transparently scaleto multiple
hosts. 61/71 I will also suggest you to include some supportedtools:
Dokku Docker Compose Docker Machine Jenkins
Questions:What is
Dockerfileused for
A Dockerfile is a text document that contains
all thecommands a user could call on the command line to assemble an
image. Using docker build users can create an automated build
thatexecutes several command- line instructions in succession.
Question: How is Docker
different fromother container technologies
Docker containers are easy to deploy in a
cloud. It can getmore applications running on the same hardware than
other technologies. It makes it easy for developers to quickly
create,ready-to-run containerized applications and it makes managing and
deployingapplications much easier. You can even share containers with
yourapplications.
Question:How to create
Dockercontainer
We can use Docker image to create Docker
container by usingthe below command: 1 docker run -t-i command name This
command will create and start a container. You shouldalso add, If you
want to check the lis t of all running container with the statuson a
host use the below command: 1 docker ps -a
Question: How to stop and
restart theDocker container
In order to stop the Docker container you can
use the belowcommand: 1 docker stopcontainer ID Now to restart the
Docker container you can use: 62/71 1 docker restartcontainer ID
Question: What is the
difference between docker run anddocker create
The primary difference is that using‘docker
create’createsa container in a stopped state.Bonus point:You can use
‘docker create’andstore an outputed container ID for later use. The best
way to do it is to use‘docker run’with --cidfile FILE_NAME as running it
again won’t allow tooverwrite the file.
Question: What four states a
Docker container can bein
Running Paused Restarting Exited
Question:What is Difference
Between Repository and aRegis try
Docker regis try is a service for hosting and
dis tributingimages. Docker repository is a collection of related Docker
images.
Question: How to link
containers
The simplest way is to use network port
mapping.There’s also the- -link flag which is deprecated.
Question: What is the
difference between Docker RUN, CMDand ENTRYPOINT
ACMDdoes not execute anything at build time,
but specifies the intendedcommand for the image. RUNactually runs
acommand and commits the result. If you would like your container to run
the same executableevery time, then you should consider
usingENTRYPOINTin combination withCMD.
Question: How many containers
can run per host
As far as the number of containers that can be
run, this really depends on your 63/71 environment. The size of your
applications as well as theamount of available resources will all affect
the number of containers that canbe run in your environment. Containers
unfortunately are not magical. They can’tcreate new CPU from scratch.
They do, however, provide a more efficient way ofutilizing your
resources. The containers themselves are super lightweight
(remember,shared OS vs individual OS per container) and only last as
long as the processthey are running. Immutable infrastructure if you
will.
Question:What is Dockerhub
Docker hub is a cloud-based regis try service
which allowsyou to link to code repositories, build your images and test
them, storesmanually pushed images, and links to Docker cloud so you can
deploy images toyour hosts. It provides a centralized resource for
container imagedis covery, dis tribution and change management, user and
team collaboration, andworkflow automation throughout the development
pipeline. VmWare DevOps Interview Questions
Question: What is VmWare
VMware was founded in 1998 by five different IT
experts. Thecompany officially launched its first product, VMware
Workstation, in 1999,which was followed by the VMware GSX Server in
2001. The company has launchedmany additional products since that time.
VMware's desktop software is compatible with all majorOSs, including
Linux, Microsoft Windows, and Mac OS X. VMware provides threedifferent
types of desktop software: VMware Workstation: This application is used
to install and run multiple copies or instances of the sameoperating
systems or different operating systems on a single physical
computermachine. VMware Fusion: This productwas designed for Mac users
and provides extra compatibility with all otherVMware products and
applications. VMware Player: This productwas launched as freeware by
VMware for users who do nothave licensed VMWare products. This product
is intended only for personeluse. VMware's software hypervis ors
intended for servers arebare-metal embedded hypervis ors that can run
directly on the server hardwarewithout the need of an extra primary OS.
VMware’s line of server softwareincludes: VMware ESX Server: This is
anenterpris e-level solution, which is built to provide better
functionality in comparis on to the freeware VMware Serverresulting from
a lesser system overhead. VMware ESX is integrated with VMwarevCenter
that provides additional solutions to improve the manageability
andconsis tency of the server implementation. VMware ESXi Server: This
server is similar to the ESX Server except that the service 64/71
console is replaced with BusyBox installation and itrequires very low
dis k space to operate. VMware Server: Freewaresoftware that can be used
over exis ting operating systems like Linux or Microsoft Windows.
Question:What is
Virtualization
The process of creating virtual versions of
physicalcomponents i-e Servers, Storage Devices, Network Devices on a
physical host is called virtualization. Virtualization lets you run
multiple virtual machines on asingle physical machine which is called
ESXi host.
Question: What are different
types ofvirtualization
There are 5 basic types of virtualization
Server virtualization:consolidates the physical server and multiple OS
can be run on a single server. Network Virtualization:Provides complete
reproduction of physical network into a software defined network.
Storage Virtualization:Provides an abstraction layer for physical
storage resources to manage andoptimize in virtual deployment.
Application Virtualization:increased mobility of applications and allows
migration ofVMs from host on another with minimal downtime. Desktop
Virtualization:virtualize desktop to reduce cost and increase service
Question:What is
ServiceConsole
The service console is developed based up on
Redhat LinuxOperating system, it is used to manage the VMKernel
Question:What is vCenterAgent
VC agent is an agent installed on ESX server
which enablescommunication between VC and ESX server. This Agent will be
installed on ESX/ESXi will be done whenyou try to add the ESx host in
Vcenter.
Question:What is VMKernel
65/71 VMWare Kernel is a Proprietary kernel of
vmware and is notbased on any of the flavors of Linux operating systems.
VMkernel requires an operating system to boot and manage thekernel. A
service console is being provided when VMWare kernel is booted. Only
service console is based up on Redhat Linux OS notVMkernel.
Question: What is VMKernel
and why itis important
VMkernel is a virtualization interface between
a VirtualMachine and the ESXi host which stores VMs. It is responsible
to allocate all available resources ofESXi host to VMs such as memory,
CPU, storage etc. It’s also controlspecial services such as
vMotion,Fault tolerance, NFS, traffic management and is CSI. To access
these services, VMkernel port can be configured onESXi server using a
standard or dis tributed vSwitch. Without VMkernel, hostedVMs cannot
communicate with ESXi server.
Question:What is hypervis
orand its types
Hypervis or is a virtualization layer that
enables multipleoperating systems to share a single hardware host. Each
operating system or VM is allocated physical resourcessuch as memory,
CPU, storage etc by the host. There are two types ofhypervis ors Hosted
hypervis or (works asapplication i-e VMware Workstation) Bare-metal (is
virtualizationsoftware i-e VMvis or, hyper-V which is installed directly
onto the hardware and controls all physical resources).
Questions:What is
virtualnetworking
A network of VMs running on a physical server
that areconnected logically with each other is called virtual
networking.
Question:What is vSS
vSS stands for Virtual Standard Switch is
responsible forcommunication of VMs hosted on a single physical host.
66/71 it works like a physical switch automatically detects a VMwhich
want to communicate with other VM on a same physical server.
Question: What is VMKernal
adapterand why it used
AVMKernel adapter provides network connectivity
to the ESXihost to handle network traffic for vMotion, IP Storage, NAS,
Fault Tolerance,and vSAN. For each type of traffic such as vMotion, vSAN
etc. separateVMKernal adapter should be created and configured.
Question: What are three port
groupsare configured in ESXi networking
image Virtual Machine Port Group– Used for
Virtual Machine Network Service Console Port Group– Used for Service
Console Communications VMKernel Port Group– Used for VMotion, is CSI,
NFS Communications
Question: W hat are main
components ofvCenter Server architecture
There are three main components of vCenter
Serverarchitecture. image vSphere Client andWeb Client: a user
interface. vCenter Server database: SQLserver or embedded PostgreSQL to
store inventory, securityroles, resource pools etc. SSO: a security
domain invirtual environment
Question:What is datastore
A Datastore is a storage location where virtual
machinefiles are stored and accessed. Datastore is based on a file
system which is called VMFS, NFS
Question:How many dis k
typesare in VMware
There are three dis k types in vSphere. Thick
Provis ioned Lazy Zeroes: every virtual dis k is created bydefault in
this dis k format. Physical space is allocated to a VM whenvirtual dis k
is created. It can’t be converted to thin dis k. Thick Provis ion Eager
Zeroes: this dis k type is used in VMwareFault Tolerance. All required
dis k space is allocated to a VM at time ofcreation. It takes more time
to create a virtual dis k compare to other dis kformats. 67/71 Thin
provis ion: It provides on-demand allocation of dis k space toa VM. When
data size grows, the size of dis k will grow. Storage
capacityutilization can be up to 100% with thin provis ioning.
What is Storage vMotion
It is similar to traditional vMotion, in
Storage vMotion,virtual dis k of a VM is moved from datastore to
another. During Storage vMotion,virtual dis k types think provis ioning
dis k can be transformed to thinprovis ioned dis k.
Question:What is the use
ofVMKernel Port
Vmkernel port is used by ESX/ESXi for vmotion,
is CSI &NFS communications. ESXi uses Vmkernel as the management network
since itdon’t have serviceconsole built with it.
Question: What are different
types ofPartitions in ESX server
AC/-root Swap /var /Var/core /opt /home /tmp
Question: Explain What is
VMware DRS
VMware DRS stands for Dis tributed Resource
Scheduler; itdynamically balances resources across various host under
cluster or resourcepool. It enables users to determine the rules and
policies which decide howvirtual machines deploy resources, and these
resources should be prioritized tomultiple virtual machines. DevOps
Testing Interview Questions
Question:What is
ContinuousTesting
Continuous Testing is the process of executing
automatedtests to obtain immediate feedback on the business ris ks
associated with in thelatest build. In this way, each build is tested
continuously, allowingDevelopment teams to get fast feedback so that
they can prevent those problemsfrom progressing to the next stage of
Software delivery life-cycle. Question:What is AutomationTesting
Automation testing is a process of automating the manualtesting process.
Automation testing involves use of separate testing tools,which can be
executed repeatedly and 68/71 doesn’t require any manual intervention.
Question: What Are The
Benefits ofAutomation Testing
Here are some of the benefits of using
Continuous Testing; Supports execution of repeatedtest cases Aids in
testing a large testmatrix Enables parallelexecution Encourages
unattendedexecution Improves accuracy therebyreducing human generated
errors Saves time and money
Question: Why is Continuous
Testingimportant for DevOps
Continuous Testing allows any change made in
the code to betested immediately. This avoids the problems created by
having“big-bang” testing left to the end of the development cycle such
asrelease delays and quality is sues. In this way, Continuous Testing
facilitates more frequentand good quality releases.”
Question: What are the
Testing typessupported by Selenium
Selenium supports two types of testing:
Regression Testing:It is the act of retesting a product around an area
where a bug wasfixed. Functional Testing:It refers to the testing of
software features (functional points)individually.
Question: What is the
DifferenceBetween Assert and Verify commands in Selenium
Assertcommand checkswhether the given condition
is true or false. Verifycommand alsochecks whether the given condition
is true or false. Irrespective of thecondition being true or false, the
program execution doesn’t halts i.e.any failure during verification
would not stop the execution and all the teststeps would be executed.
Summary
DevOps refers to a wide range of tools, process
andpractices used bycompanies to improve their build, deployment,
testing andrelease life cycles. In order to ace a DevOps interview you
need to have a deepunderstanding of all of these tools and processes.
Most of the technologies and process used to implementDevOps are not is
olated. Most probably you are already familiar with many ofthese. All
you have to do is to prepare for these from DevOps perspective. In this
guide I have created the largest set of interviewquestions. Each section
in this guide caters to a specific area ofDevOps. In order to increase
your chances of success in DevOps interview you need to go through all
of these questions.
docker login –u
username(dockerHub username) 
